I am currentlly registered with two or three products on Clickbank, but I haven't sold a thing yet. At least the last time I checked. Since I don't have the money to do PPCs and SEO advertising, I have to rely on free tactics, those are rather time consuming. But they can and have worked in the past.

It sounds like you have not been putting much effort into this. If you really want to be succcessful in it, you need to allot some time to promote your products. If not you will always remain exactly where you are.

Karl is right, the key is to offer the affiliates a good payout so you get more sales.

Without a good payout, people won't advertise your products. Give a good payout, a great product, and amazing customer service and you'll have a winner.