I don’tlike iframes a lot and also hosted solutions are only sometimes nice when the company has a lot of action in their offers. At the end, my favorite kind of advertising is hosted on our server and also never with affiliate-link, because my experiance is that people just like more clear links like company.domain.com or domain.com/company, how ever you like. It looks more serious and is easier to use for us in some cooperations with betbrain, because then WE only have to change a link when a company is changing the actual offer. 
Also………I see no reason for giving pageranks and backlinks 