TF2 was a masterstroke for Valve in PR. I paid $40 for TF2 and I felt like the value that it gave over the past 5 years has more than exceeded what I paid for it. It has generated a huge amount of goodwill towards Valve and Steam that will help anchor them in the PC gaming industry for years to come. It will be interesting to see where they're taking Steam and the PC platform in the near future, especially given all the talk about a possible console.