I was discussing this with a GM one of the servers I frequent and apparently giving in-game incentives for reviews is frowned upon and, at worst, a list-removable offense. While I realize that RMS is a separate entity all its own and does not necessarily have to conform to any sort of standard, we all have to realize that the precedent has been set by the voting reward points. Even though it is in several ways inherently flawed, it is an overall effective way to promote a server and every party involved can benefit in certain ways.
If you're not familiar with the voting reward system, various servers try to get their names up on top of the other websites that list them based on voter popularity. The rewards, in turn, are often tallied in the form of points (or whatever currency you are more comfortable with), usually a static amount per vote, that can be exchanged for various items and features within the server. The process by which one can get these points is ideally slow enough that it doesn't conflict too much with the zeny economy, yet is beneficial enough so that even newbies can become established relatively quickly. I have to stress the latter point because so often servers are not newbie friendly and it's mainly for that reason that their populations stagnate to the point of oblivion.
I don't mean to give my favorite server a shameless plug, but TalonRO is an example of a server that implements the voting points system well, especially for the fact that the GMs go out of their way to modify the exchange value of the point system fairly regularly in order to maintain both its own worth as currency and the continued necessity of zeny. In return, we, the players, are rewarded for our continued loyalty and longevity to the server [On that note, I noticed on the side, it says "longetivity" which bugs me only because I'm rather OCD about spelling. I'll probably go over this entire response at least 5 times to make sure it's all right in that regard, but I digress]. For all the server owners that do implement that system and do it well, I applaud you and your supportive players.
Many people will try to invalidate this concept for RMS server reviews in that the potential for abuse is high. I agree with the notion in that the influx of positive reviews will surge tremendously, but I can think of a few of safeguards preventing the ordeal from being so extreme that it becomes unmanageable. First, limit the ability for us to submit a review for the amount of days that seems reasonable based on the increase in the amount of reviews. Second, provide the in-game incentive for all legitimate reviews. Thus, people are encouraged to be honest and they still benefit from their efforts. Third, have the reviews be screened to the extent that the ones lacking any beneficial substance whatsoever are not worth rewarding (both RMS and server owners can work in concert to make this effective, but I admit the amount of effort might seem exorbitant... however it's a great way for one server to stand out from the rest- also with the increased amount of reviews, there might be the few that provide legitimately vital concerns that server owners can more readily address). Fourth, an IP tracking system that prevents people from utilizing multiple accounts to game the system can be implemented, if it isn't already.
The fourth point is something that most people enjoy contesting, and I agree that it's a great cause for concern, especially given the substantially greater temptation for abuse that will come about as a result allowing RMS review-based in-game incentives. However, I don't think that it will be as great of a problem as some might assume and I will explain why.
Given how the top servers only have only a hundred or so reviews, that number will hypothetically rise in a significant way if top servers decide to latch onto this system. Since it will eventually become a requirement for servers to be noticed, others that want attention will do it as well. Consequently, the number of increased reviews will better reflect the population of each server and give a better and more immediate impression about the community, in a quantitative sense, within each server. The multi-account reviewers that get away with it will still be able to do so, but their efforts will be less effective. I understand that this does not solve the problem, but I admit that I am not knowledgeable about programming and website building enough to really suggest much to counter it.
What I do understand is that the ability for people to abuse the review system has always been there, and I sincerely believe that doing so is much more effective at deterring people from ever playing on the server currently than will ever be, if the RMS review-based in-game incentives system is not only allowed, but becomes mainstream, since there is, for now, not a great deal of player response to counter the sometimes unjustifiably harsh reviews.
On that note, one of the issues I noticed with RMS is that the reviews do not necessarily reflect the population count. I won't provide any examples even though I am guilty of doing so before, but some servers with twice the reviews of another can somehow have the same population count. I didn't go as far to consider the variables of merch-characters and how new the server has been listed, but those discrepancies can be much more quickly and passively addressed by utilizing RMS review-based in-game incentives. Also, both the server and RMS can benefit from the traffic in however many ways they choose, unless they are adamant about paying out of their own pockets to eliminate the need for advertisement of any kind.
In conclusion, I want to state my appreciation by saying that RMS is still the best resource for people who are looking to play on private servers. Even though I am criticizing its traditions, I only want to see this website and its community become better. I also am open to the possibility that I am wrong or did not account for any foreseeable consequences that may render this idea useless. If I have, then I ask that you respond with the same civility that I have expressed towards you, the readers, RMS frequenters and potential friends. Thank you for your time and have a great day.
P.S.
Sorry of this idea has already been argued through and addressed. I admit that I did not do a generous amount of thread-searching to see if someone has brought it up already, but for what I did, I could not find anything similar.