Thank you for your feedback Ian. I know you've been in this field for a long time and know more about it than almost anybody else.
I agree that postal costs are higher in the UK and that's why I mentioned it in my original post.
Still doesn't justify massive differences in commissions between the UK and US. Before affiliate marketing I spent four years working as a journalist for a magazine. We would earn thousands of pounds for a b&w quarter page advert. Advertising is what pays the employees wages, not cover price. Many magazines you can been given away for free and they would still turn a profit. Companies like EMAP are making millions of pounds in profit on their magazine subscriptions. Therefore 5-7% commission on cover price, IF the sale goes through and tracks, for affiliates doesn't seem fare. We're not getting a big enough piece of the pie.
IMHO the magazine industry in the UK is too cosy and not dynamic enough. Need more people like you Ian. Like you say, they still haven't got their online subscription efforts into full gear. Many employees of magazines I know didn't get their jobs because of talent, but because they or daddy had a contact at a particular publication.
Still, if that's the going rate in good ol' Blighty then we'll focus on the US market. Choice A: 5-7% commisson, Choice B: 30%. Which one would most people put their efforts into?
One thing I must praise UKSubscribe for is the speediness of support for their affiliates. I emailed Ian on Sunday evening and got a reply almost instantly

That's why we prefer UKSubscribe to the others.