F2P games are not evil nor the bane of the gaming community. It all depends on how the developer implements it and tunes the system. If you want to see an amazing implementation of the F2P system just look at Turbine who's taken several near-failing games and turned them around. DDO / AC / LOTR.
I use DDO as my "casual MMO", the place I go to play during short 1~2 week FFXI breaks (prevents burn out). I'm a VIP subscription because I believe in supporting the company, so for me it's basically a subscription game though that doesn't really give me any gaming advantage over F2P players. Their different levels of subscription are.
Access to all vanilla worlds and dungeons, access to most class's / races.
Must spend turbine points to unlock additional class's / races / dungeons / quest packs.
Same as F2P except you've bought Turbine points at some point in time, have access to whatever you bought.
VIP (12.95 a month I think)
Access to all area / class's / races / quest packs, no need to individually purchase them
500 Turbine Points gifted per month
Turbine points are either bought on their store, usually with sales happening frequently through out the month, or you can farm them in game. Farming them is time consuming but not SE FFXI stupid time consuming. You naturally acquire turbine points just by playing and questing, the games entire XP system is based on quests not grinding the same monsters. Completing quests gets you XP and Favor, Favor translates into Turbine Points which can be spent on quest packs / builds / class's / races.
The idea is the game rewards players for playing but doesn't penalize players for taking a break. You get rewards for the time spent, you can play money to accelerate that process if you wish, or you can just go to regular subscription access and bypass the farming points, although you can't bypass the questing for XP system.
Items points can buy
+4~+5 Equipment (stupid cheap in game, anyone who buys these on the store is stupid)
20% XP boost potions (lasts 3~6 hours, typically not worth it)
20% Loot Boost potions (lasts 3~6 hours, not worth it)
Extra Inventory Bags / Bank slots (might be worth it, I bought one with spare TP then later ran across the quest that game me it for free, felt stupid)
Monk Class / Drow Race / Half Orc Race (might be worth it if you want to create a new char, easy to farm points for in the game)
Quest Packs (only thing legitimately worth spending TP on as nobody wants to wait the month or so it takes to farm the points for access)
+1~3 Stat Tomes (appear powerful on the surface, by the time you can use them you can find them in loot pools and farming)
Reincarnation Items (worth it if you made a mistake and need to reroll / respec your character aka "first toon syndrome", can be avoided by careful character planning)
Guest Pass's (allows a sub player to invite a F2P / non-access player into a quest / dungeon, another legitimate use of TP)
Best gear still comes from high end elite / epic raids, no way you can purchase it or pay for it. Your basically paying to accelerate and by pass the time sink that is farming TP.
The key is to make a game that is balanced as a subscription model, then create a store where subscription-less players can obtain everything a subscription player has. What this does is inflates the player base substantially while not ignoring the dedicated players. More players online means more things the subscription players can do and less "waiting for a healer / trap rogue to LFG". Dedicated players leave games when they get bored and are unable to participate in content (or there is no content for them to do), keep them participating and they'll keep paying sub fee's. Use point systems to get casuals into the game to create larger player base's to serve as a recruiting pool for the hardcore players.