Your affiliates are the most important thing to become successful. You must contact them and give them a motivation all the time.
If they work, you earn. This is a team work. I think you will increase you earnings if you motivate your affiliates and of course doing your daily activities.
Registering new affiliates (active affiliates) explaining the first steps, helping them to make first VersaPoints and gifts, also.
This is my theory and I think that is a way for increasing SFI earnings.