I agree that creating your own product giveaway is the best route. Even something as simple as a recorded webinar series has a lot of perceived value and is actually not that hard to do at all.

Another option to think about -- and something I have done -- is to create a membership site that is primarily PLR and MRR content that is put together in a very neat, organized, and cohesive fashion. Have a public price on the membership site but give free memberships as the bonus. There is a very real value to the bonus now because people can see the public membership price to get access to the site and they get access free.

Just some ideas!