The ideal Free 2 Play model is one where paying only gets you cosmetics or "side-grades" that focus on customization rather than upgrades. That business model may be less likely to generate profit, but it's much healthier for the game experience.
Seriously check out Blacklight: Retribution if you haven't already. It pulls off a palatable F2P model very well. You unlock new stuff without paying at a pace that maintains interest. If you play 2-3 hours a day, you'll get a minor customization every couple days or a new weapon a week or a piece of armor or something after a couple weeks. That's the maximum amount of time it will take you. Not a single item in the game feels like a linear upgrade. They all have equivalent bonuses and penalties, and only really serve to cater to play style and give you stuff to toy with.
League of Legends is probably the most successful example. Purely cosmetic marketplace.
Planetside 2, on the other hand... it feels like it will be months before I have even a single class with halfway upgraded utlities and a 1000 cert weapon, if I put in comparable hours, and everything is linear upgrades.
But anyway... I did just log out of the game after a really fun session. I went off capturing undefended facilities as an infiltrator again. There was another guy doing the same thing, so we teamed up. We captured like 5 areas together before moving on to our first major battle. Suddenly our squad grew to max size, we got invited to a platoon, and I was really starting to look into coordinating things. Too bad I had to leave not long afterwards. That was getting really fun. I think I'll make greater efforts to get involved like that in the future. It may convince me to stick around. If only people used their mics more. I was the only person who talked. Come to think of it, that's probably why people ended up following me.