hmmm

Pros:
- Having a better idea who's promoting the sites
- Better idea who/what the traffic sources are
- Keeps out the fake webmasters who come looking for free content and free passwords
-

Cons:
- Time consuming to talk and check each affiliate closely
- Less overall affiliates promoting
- Missing on otherwise good affiliates who decide not to join because they don't want to take the time and go trough the approval process