Will Facebook offer incentives for activity?

They don't need to. Even if they don't give incentive to members they are already successful to any other site. And I think they won't give any incentive to further increase their members and members activity. Same as what happened to friendster they know that they're already losing to facebook as early as 2006 and in 2011 they completely change their site into a game based site almost same as facebook but still they keep on losing. They didn't try giving incentives to their members (to increase member activity) because they they know that it's not the way social networking sites are and it would affect their reputation(maybe). The big 3 networking sites facebook,myspace and friendster are not giving incentives to their members but has lots of active members that's still a big question here.

No idea, but I don't think it will because it's already so popular. Incentives for activity would probably work for a new website or a relatively unknown website.

If Facebook starts to give any incentive, then I think a lot of new rules would be introduced. Too much and too strict rules, meh, it would be less fun. I guess Facebook would lost much of members if they are starting to give some incentives.

I hope they will offer incentives for activity. I have been using facebook for a very long time and they haven't rewarded me anything. The site will be more popular if it introduces incentives. I believe mylot is becoming popular because of the incentives that you get.