This is one of the most powerful questions as far as sponsoring and sales in SFI is concerned.
In my humble opinion,i think the best way to attract potential family and friends to SFI is to approach them politely with your master card with SFI logo.90% of them tends to see before they believe.Another tactics is to register in WAVE 3 with your picture and SFI images attached to it.
Hope this will convince them that you are making a living with it.