Lingo
Free 2 Play (F2P)- A game that is free to everyone. ff used as an adjective it means: a player who hasn't spent money to get an item.

Pay 2 Win (P2W)- Describes a game that gives an edge to players who spend real life money. While not impossible it is very hard to fight a Paying user as a free user . (MMO's tend to be P2W although not all are.)

Pay 2 Play (P2P)- The worst type of game it is a game where Progress is slowed or halted unless your spend money. This can be done by either making the game near impossible to play unless you spend money or they put up a massive pay wall. (this is seen mostly in mobile games, where they force the player to wait unless money is spent to speed up progress, some MMO's do this as well)

Pay Wall-This means you cannot continue the game unless X amount of money is spent.

Note:Games can be Free2Pay and Pay2Win or Pay2Play but typically games that are Pay2Play are far worse than Play2Win and so the terms shouldn't be used interchangeably.

Intro
Anyone who owns a server wishes for their server to grow and one day be filled with people that will come back day after day hungry for more, however as everything else in the world this is not free and it will cost money to keep a server running. After you pay to have your server run 24/7 you may also have to pay for things such as more ram or keeping a server website running. All of these things are essential to keep a server from stagnating and eventually dying out! So a solution to this is to have the faithful player base donate some money to keep the server afloat and this is where Corruption can been seen slowly slipping in to our minecraft community.

Here is a scenario:
Let's say I join a server. Everyone welcomes me and I make some friends eventually staying for hours. It turns out the server owner needs money and so everyone pitches in and we get enough money to keep the server afloat....HAPPY ENDING.

Now have a more realistic approach:
I join a server and the first thing I see is "DONATE TO GET ___ RANK!!! GET A FREE KIT EVERY 24 HOURS" .......*disconnect*

Donating
Keeping a server afloat by giving the owner money.

Can we address something that irks me? If you donate something and get something like a kit or diamonds in return you didn't donate. YOU PURCHASED AN ITEM!! Donating is when you give money to something or someone and expect nothing in return but donating just to get a rank isn't donating, you're just buying something. For example you wouldn't give some spare change to a homeless man and expect a service in return!

Now the whole "its not actually donating thing" is not what i have a problem with. If servers were dependent on true donations to stay up 98% of minecraft servers would go down within the month. So I understand if you need to spice up the deal a little. A [Donor] rank and other cosmetic upgrades are reasonable rewards that will not give you an edge against that F2P player who has clocked 1000 hours in the server so that is a respectable way to get donations.

Then you get those servers (usually pvp focused servers) that have upgrades that make the game Pay2Win. Getting a custom name or other cosmetics is fine, but getting enchanted diamond armor is OP.

Making donation rewards for your server? Here is a pro tip:
YOU SHOULD NOT GET A LEG UP BY PAYING REAL MONEY!

This is also a big problem in large servers where if someone calls Pay 2 Win they get drowned out by by the hordes of worshipers making up excuses for the staff. If you really think the server isn't Pay 2 Win then the points someone else makes should be easily disproved.


Premium Currency:
Currency only obtainable by spend real money!

The more you work for something the greater the satisfaction is when you eventually earn that item, however the more you work the more you want the item. This is where money comes into play because if you can speed up the process and get an item a bit earlier then you are more likely to spend real life money to do so.

Mobile games know this and do things like include "Gems" or other Premium Currency that can speed up progress and get you item faster which is kinda Pay2Win but what makes it worse is they do something like extend the wait time on buildings to tempt you to use "Gems".
"Yeah its gonna take a whole week to build that ,but if you spend only 10 gems it can be done right now!"
This makes a game Pay2Play, it's unplayable unless you spend real life money or have the patience of a Buddhist monk.

So what does this have to do with minecraft? Well everything... You see Premium Currency is only seen in large servers for the most part I am talking 1000+ players everyday, however when something is so successful its bound to spawn copycats and although rare I am starting to see servers with 25 slots max have Premium Currency......

Item Crates:
These crates are what they sound like crates filled with items.

This is not a problem if the items are cosmetic, along with fair donations it can be a great way to make the server money. Popular games like Team fortress 2 and Counter strike:Global Offensive do this. They offer a crate which have cosmetic skins that vary based on rarity. These skins are purely cosmetic and don't affect game play. So a player that hasn't spent a dime on the game has the same chance of winning against a person who spent their life savings. Some servers offer other types of item crates however. These item crates may have real game-play items and not basic items that offer small help such as 10 pork-chops or 10 logs they can offer things like OP swords or OP armor. making you want to buy the crate, but the worst part is when they do this and make the OP Sword something like a 1% chance of getting.
"You want me to pay $2 for a crate that has a 1% chance of getting a sword... no"
*gets killed by the guy who spent $200 buying crates to get the sword*

Voting:Saying this server is the best and should get more players
"Whoa whoa you have a problem with voting??"
Yes and no, you see, I have a problem with serves that offer huge rewards for voting. Voting use to be a way to see which servers are the best and deserve more players, but now, they are more of an indicator of what servers offer the greatest reward. Every single server has a voting reward which is weird, because if you were to try and buy votes like this in real life, you would get arrested in a heartbeat! How is this allowed?! Voting is saying this server deserves recognition it's not suppose to mean "Yeah i just want stuff so here" It just baffles me that no one has spoken up about this. Yes voting is great and helps servers, but this is just absurd! Honestly I would suggest not judging a server based on votes...the people were bribed to vote.

Ranks:
Ranks are a symbol of status, representing experience or authority. These ranks are often in 3 groups in minecraft servers (Experience, Donations and Staff).
Staff:
Staff members are the highest tier ruling over the server and receive respect from most people automatically these are ranks given to only a select few and should not be obtained by money. Staff members can also give or take ranks depending on the actions of a person or events that take place.
Experience:
These are ranks that must be earned and the higher ranks of these tier require a great deal of effort. These ranks are not earned by money.
Donations:
These are the ranks that can be purchased with money. They are rewards for supporting the server and are either the easiest or hardest ranks to obtain depending on the amount of money you have. These ranks should be treated as respect, they've helped the server by donating money and so have solidified the fact that they support the server.

Community Division:
These ranks are important to a server as they let others know about the player for example you would be more cautious about what you say to a staff member it's just natural to do so. One thing I've noticed though is that donator ranks often replace ranks earned through experience and when I've gone onto the forums of some Pay2Win servers they is a large amount of community division.

Donator ranks seem to be valued higher than ranks earned through experience even though they show no indication of wisdom. I could go to many servers spend X amount of dollars and become top rank in an instant. I would probably get a title like [Legend] and immediately place my self as being higher than others who have been on the server much longer than me. Donators tend to have a bit more pull than those of the "Free" rank simply because they have donated money.

So along with the in-game perks i also get a higher pillar in the community and join the "elite" this is not a guaranteed perk it is just a side effect people who donate high amounts of money are automatically seen better than a normal rank due to how much they supported the server.

This can be dangerous for a growing community as it may feel the donators are getting priority over others. Community divison can be a server killer as everyone feels wronged the F2P feel that it is unfair that donators are getting special treatment and the Donators feel as if they are being punished for helping the server. In truth it may be that the F2Ps are wrong and the Donators are not getting special treatment they are just finding evidence they wish to see.


Final thoughts:
All of this is frighting. I am a minecraft vet started playing in 2010 on my friends account (he let me have it) then bought my own in 2012 and I remember servers being mainly about the game sure donations were a thing, but they didn't break the game it was a time where they were far less pay2win servers and donation systems were not as advance as they are now. We as a community have come so far and here we are 2016 and with 70 million players and rising minecraft is a gaming trophy its just sad to see it starting to get corrupted a bit. These greedy tactics start off as small and only in a few servers, but if ignored will become the norm. Just look at what has happen to games recently: Season passes, game content cut out just to make it into DLC, MICRO-TRANSACTIONS!! None of this was in mainstream gaming 10 years ago and now it's practically essential for every Triple A game! I fear that Minecraft is headed down the same road with more and more servers adopting these greedy tactics .
The real question we have to start asking is:
When does asking money to keep a server running turn into, tricking players using shifty tactics to get money and turn a profit..


Common comebacks:


"If you don't like the server's donation system then leave!"
I do and the servers dont last long soon after that, because people wise up on how unfair the server is and leave it to die, but not before some people buy some items and make the server owner money.. This is not how minecraft servers should work they should not be made for the sole purpose of making money you've already payed for minecraft why do you need to pay more just to enjoy multiplayer? Besides if a P2W server is successful that just breeds more P2W servers looking to get money like the big boys.

"So you hate the fact people support the server?"
No supporting a fun server and feeding a greedy server owner are two different things if you donate to a fair server and the rewards you're given don't make you op, then you are supporting a good minecraft server that seeks to make the game fun rather than line the server owner's pockets.
If you support a server that sells kits and ranks under the term donating then yes I hate the fact that you are supporting a server that promotes this P2W system the more money a server owner makes from a P2W servers the more likely they are to make another and thus stealing potential players from other servers that are not Play2Win.

"Why should I listen to you? you don't make the rules!"
No i don't make the rules, but are you honestly going to defend a system that seeks to take money from players rather than provide an actually gaming experience? Pay 2 win is not strictly a minecraft thing. It's a plague in gaming mostly in MMOs they ruin the game and just make gaming suck in general because your kill streak is ruined by someone who got the donator weapon or perk.

"Your dumb"
You're*

I can answer additional questions in the comments and ill update this more when i get the chance

TL:DR
Just read it i mean come on some useful info in here, but oh well.
Don't support pay2win servers
If you donate money and get something in return your not donating
Don't make a minecraft server just to get money (Your adding to the growing cesspool of bad servers looking to become hypixel or mineplex)
Stop with the premium currency
Why is it ok to bribe people to vote for your server like WHY!!!
btw i did want to dig into certain servers a bit but thought against it as attacking specific servers is kinda a jerky thing to do