Facebook is rolling out "Buy Ticket" buttons to users with Event pages. Clicking on the button takes the fan to third party sites to buy tickets, and event creators can choose what link to add. While far from revolutionary, the addition of a clear buy button should increase ticket sales.
Users of popular musician Facebook apps like BandsInTown, Songkick and BandPages can already add outgoing links. But the new feature is yet another example of Facebook's ongoing interest in commerce on the social network; and of it's wllingness to add features created by outside app developers.