Personally I would tell them to join the site, take some time to look around and they will get all the information they need with regards to what SFI is all about and how to best utilize it.
The draw of being able to earn a residual income from a site that's been online for over 16 years and is free to join should be all the information you need to give anyone to get them interested, the SFI site itself will do all the explaining for you
