Free trials, or low cost trials aren't necessarily the key to a successful business model or success with affiliates.
Take a look at any of the
Teen Revenue sites. Go through a tour as if you were a surfer. There is no trial offered up front. Only when the join page is closed does the potential member see a trial offer in front of them. It's not a standard 4.95 trial either. The price is higher, the trial longer. This method working has a lot to do with the nature of the site and it's content. In our case, the content is 100% exclusive so the method works very well.