No.1 Question about Membership Sites?

Hello,
the best question to ask is how to retain members on a long term basis.
It costs more to find a new customer than to keep him as a regular member.

Here are a few I have come up with - these are things I would genuinely want to know if I were on the verge of starting a membership project:

1. How can you tell if a particular niche is suited to the membership site business model? Does this have any effect on the way you do keyword research?

2. What are are the pros and cons of having a member forum within the site?

3. What are the best methods to ensure fair distribution of products and advantages so that everyone who joins gets more or less the same for the money? For example, I have often seen situations where if one joins when the site is fairly new, they might access a download area that has 3 or 4 products, whereas one year later that same area now has 20 products immediately available to new signups.

4. Is it best to shop around for different scripts and softwares to handle various tasks such as payment processing, upgrades, content management, support, etc, or are there reliable, cost-effective programs out there which will handle pretty much everything?

5. What are the pros and cons of multiple levels of membership, e.g. free, bronze, silver, etc. and does this work better with some niches than others?

6. Obviously people will inevitably drop out, but are there any good specific strategies for somehow keeping them in the loop, for example by exposing them to other offers which might suit them better?

7. Assuming all goes well and it really starts to take off, are there any key danger areas to we need to plan or look out for to stop a membership site becoming overwhelmed by its own success?

Hope this is helpful
cheers
Ken