Server recommendations that can bring in revenue to the community.
Counter-Strike Servers (CS:GO)
-Jailbreak
-Mini-Games
Garry's Mod Servers
-Jailbreak
-Deathrun
-Dark RP (kinda risky but potentially worth the investment)
-Purge (Not RP, more of a base building/teams up to 4 people killing each other, Tango, my old community, did something similar to it and it brought in a lot of money and it was just a fun game mode in general and would like to see another community do something similar, since Tango's purge server died due to poor management and favoritism in the community. It may need some tweaking for the plug in, but I think it would be well worth it. Another thing to note for why Tango's purge died was because they also changed weapon packs multiple times, which reset the stats for everyone and it ticked off the regular players, which is something to learn from other's mistakes).
These are just the main game modes that bring in revenue and people into the community if executed correctly, emphasis on executed.
Ways the servers can bring in revenue:
-Ads on MOTD for Garry's Mod (It may seem unprofessional, but the larger communities such as GFL Clan is doing it on there servers and it's becoming a bigger trend). *I also want to note that ads and monthly/quarterly/yearly subscriptions have a more consistent revenue stream.
-Have a point system for Garry's Mod and CS:GO servers
For Garry's Mod, there is a couple of ways you can approach this, you can have your donators pay a certain amount for donator points and benefits, and or have a monthly subscription for it where the donators earn donator points for playing for X amount of minutes or hours, increments can vary. There is also the option that players can earn cases for trails and player models, but need to spend so many points or donator points to get the key to unlock it, which also gives you the option to add keys to donator's perks.
Counter-Strike, on the other hand, has a little less variety for donator perks and all that. You could have a point system implemented in place as well, for player models and tracers, and donators get double points earned, a percentage off certain player models, or exclusive player models/trails/tracers.
-Back to Garry's Mod, this mostly pertains to the Deathrun server, but can apply to the Jailbreak server, you can have skins on knives, which also goes back to the point system, but you can have certain skins exclusive for donators to earn to add an incentive for donating.
The whole idea of having a point system in place is to keep players grinding and staying for awhile to earn different cosmetics or items in the servers, which should help population a little bit, but you will need players already on the server to help.
Events is another key factor to keep people playing, whether it's giveaways, tournaments, or etc. This will also keep people playing on servers and rewards people for staying on.
*I want to reiterate that the servers need to be executed well and have other community members playing on them to attract new members, as well as potentially doing advertising, whether it is social media or trading websites.
I was also talking to some other community members a couple days ago, and I heard that the community only has one server box, another would be worth the investment, but it would be a slight risk to over extend to quickly and not have the management for the servers, which can pose a problem.