What they are:
The most successful affiliates are ECAs and/or Team leaders.
What they do:
What I have also noticed about the leaders in SFI is that they log in daily. They are E365 finalist. They have a S-Builder co-op and a standing-order.
Where they are:
This means they are likely to be at the top on the power ranks.
They are visible on the Forum and the Pricebender auctions.