Legion said:
Free avatar items, themes and gamer pics would probably do it. Small, meaningless incentives that would otherwise cost the gamer a small amount of cash.
I honestly think it would work, people like small pointless free things.
True, but the problem with 'Project 10 Dollar' and what Epic did with Gears 2 and even what Cliffy is talking about to an extent is this:
What if you don't play online? Or, more to the point, what if you don't HAVE an online console connection?
I do, and I'd expect most people here do. But unless it's something like physical items in a collector's edition, digital content is not always the way to go. Maybe if you have a one time use unlock code in the box that you register on a website, that might work. But again, only if you have net access in your home. It's great to assume people do and I for one think it's essential. But I'm not everyone.
The other thing is talking it up. People need to know about the existence of it. Something THQ did rather poorly with UFC Undisputed 2010.
And finally, make sure those codes don't expire anytime soon. I understand the appeal of not having those codes last forever, but people buying new copies of Dragon Age will be interested to note the codes for Shale/the Blood Dragon armor expired at the end of April. That could be some agreement worked out with Gamestop; after all, being at war with the main company that distributes and sells your game isn't exactly a very profitable sounding idea. Still, it's something to keep in mind.
Ultimately, content you can buy at a set price discourages but will not eliminate used sales. Reason being: Gamestop/whoever can just price drop the game. In Canada, pre-owned copies of UFC 2010 are 49.99, new are 64.99 at EB Games/Gamestop. So with the Edge card, you're saving upwards of $20 versus new, and the online code is $5. So you're still saving plenty.