By now most of you have your opinions on free-to-play "F2P" players in TF2. Like some other gaming platforms, Steam has been morphing into a free-to-play & pay-for-content system. The game's development was intended this way. Like it or not the F2P system was very intentional and because it worked, actually saved TF2 so that we still enjoy it today.
Gamasutra has a great article
here that explains Valve's strategy as well as this head-turning statistic: TF2 makes 12 times more revenue per month as F2P than it did when the game was sold outright. Yes, twelve times more. Another interesting thing is that they do indeed gauge community support and interest in items and gameplay by monitoring forums. You rarely see news with real data that normally would never be published. Give it a read.