> They still needed a solid business plan how to earn money from Flickr...

SmugMug, by their own admission, bought Flickr to help keep it alive. Currently, they're not even looking to make money but reduce the operating costs. I'm sure they didn't take the decision to move to AWS lightly, at all.

> ...this kind of looks like they've thought of asking for money AFTER the move.

May be you're right that it might have been a mistake, but the fact that SmugMug are a heavy AWS user means it might have made a lot of sense to leverage not only the engineering and operational expertise but also the heavily discounted rates they must have negotiated with AWS?