That would still be a redirect I'm afraid, and Google would disapprove the ad if it spotted it.

You might find that some merchants will allow their brandname to be used as a directory name as you've suggested, and others will also allow it to be used in a subdomain name - merchant.example.com, and others will disallow both. These relate to landing pages of course though.

It sounds like you've done a fair bit of PPC so you probably know this already but it's one of the the tough things about PPCing that there are some merchants you'd love to promote direct and you just can't without getting into dodgy areas, or even worse you get a great campaign going and their rules change later and you have to turn it off. Been there, got the t-shirt.

On the positive side there are new merchants available all the time and there still some room for making a living in this way, although it seems to be getting a little bit tougher all the time with added competition from new affiliates and agencies.

Good luck with the other networks. I suspect you'll find them as good or better than TD.