Purchased Sebastian Foss' 'Income Builder' which came with 100% guarantee of money back if you made no money. Sales page also said it was not some affiliate mumbo jumbo which, in reality, it is.
Promoted the product using adwords and ended up $100 out of pocket plus the $49.95 purchase price of income builder.
Decided to contact company using the email address given for any problems which might arise but have heard nothing. That was 3 weeks and 7 emails ago!! Also tried the contact form on website but still no reply. The last email I sent was to inform them that if I had no reply then I would name and shame them!!
They obviously still have enough people buying to not care about the people who do try to put the 100% money back guarantee into use.