I would initially invest in an EA qualifying purchase, while using free advertising to get the word out about SFI.
I would then use my commissions to purchase the more favored paid advertising to increase my downline.
Why did I do this? Firstly I did not feel I knew enough about SFI in the first month so I spent my time learning all that I could. Then when I got affiliates I had the knowledge to assist them in the best way possible.