I love the fact that tickets to almost all sports/entertainment/music events can be purchased online now. But what if your audience isn't very web-savvy? Even if you make the purchase process as simple as you possibly can, people still may get confused. Or maybe they just don't feel comfortable yet, and are afraid they might mess up.
A very simple solution to implement here is to create a brief screencast/tutorial video to walk people through the process of buying a ticket (or whatever it is that you want them to do). This video should show people exactly what they'll see on their computer screen and break down the process into simple steps. You can use free software such as Jing (I use this on my mac), or you can buy something like Camtasia Studio, which has some great additional features, but is only available for Windows at the moment.
These step-by-step tutorial videos can be a great tools in getting people to try something new or encourage them to do something they wouldn't do otherwise. Maybe that's buying a ticket online, or maybe it's uploading a picture to their profile on your website. Sure, a lot of people know how to do these things, but you might as well provide help to people who don't--there's still probably more of these people than you think.