My guess is that the profits from the referral link goes to Gates foundation for charity.

Its possible he's using some site wide tool to monetize and that added the link automatically. Though the graphics suggest he did it with some forethought.

I think its also kind of funny that I stopped reading this article half way through and jumped to the link since I was so curious if it was going to have a tag code. That says a lot about the nature of affiliate marketing.

BTW, I don't see anything particularly wrong with it.

As a general rule, do not trust recommendations made by powerful people, be they magnates, presidents or generals.

They are all politicians (or else they wouldn't be where they are), so everything they do has an angle.