The ads on this site are dynamically rendered based on the content on the page - I don't control them.
To answer your questions, there are a few reasons one might call them a scam:
1. Some people paid money and received nothing.
2. They don't openly state that it is a homemade (many believe it is official).
3. They tell a lie about some UK Company owning the rights to the show.
4. They change web site domains every few weeks.
That said, some people claim to have received discs and were happy with them. So buyer beware - you can make your own decision about whether some of these offers are 'scams' or not.