I don't think it is ever a bad idea to give people a sample of what they will get before breaking out their wallet but as far as offering them full length videos? I don't think I wouild give away full length videos. I mean, a few will not hurt (depending on how much content you have) but for the most part, I would stick to giving away sample clips. You should create promo galleries with sample clips and promote them across the web yourself as well as getting affiliates to promote them too. Make sure that you have a banner link leading to your site so that if the surfer want's to see where the video came from, all they need to do is click onto the banner to be taken to your site. And even if they do not check out your site right away, whenever they view the video, they will always see the watermark representing where the video came from. If they like it that much, sooner or later they will check out your site.
There are many ways of getting your content out to the surfers (and I have various ways of marketing my stuff) but I get alot of sales through the promotion of my promo galleries...so that is what I would do if I were you.
Good luck to you!
