Self financing Mortgage

Hi,  Has anyone come across this website / company and can they offer any advice / information about their claims. 

http://www.bosolhipotecas.com/site/en/easy_living_plan.html

If I understand it correctly, they are saying that 80% of the value of the propert is invested giving a return that is more than the monthly payment on the mortgage.

Is that right, what's the catch????

Kelju