Many entrepreneurs try to sell memberships directly to customers. If you are having trouble getting sales this way, a suggestion is to try and sell an inexpensive product which would be a small impulse purchase. Then try to upsell them on the membership as an add on, and also in future emails using an autoresponder.

So for the cheap instant access product (say $5) you can pull out content from your site and test different individual products to see what is selling better and that leads to more upsells. Try a wide range of products in your niche.