I suppose it depends on the price point. You're right that some people are happy to promote Aweber and Amazon, but most of these people don't mail out to their lists telling them to check out "this cool autoresponder service" or "this cool gadget on Amazon". I'm not sure about this, but I'd say most affiliates for these sites get their sales passively through blog traffic, PPC, or organic search traffic for example. Their money comes in without the effort of having to mail for and personally endorse a product, so it's not so bad that the commission levels are lower for such affiliate programs.

If we're talking digital products like what you want to sell, I'd say be as generous as you can. Trust me - a $17 ebook at 50% commish is going to be a hard sell to affiliates. On the other hand, this same commission rate for a higher ticket product ($47-$97) would be more acceptable.

For the back-end membership's commission level, the price point matters as well. It's tough to say without knowing what your service is, but again, I'd say be as generous as you can. Can you share some details about this service?

Curtis