Perhaps this is the deal that Lisa referred to last week (a few of her images were selected and she had to commit to leave them on FT for one year)?

I assume she was somehow compensated for this - i.e. they may be free to Microsoft users, but they weren't provided for free?

Yes, the deal Steve-Oh describes is how it works on Fotolia too. 

They selected 7 or 8 of my images and I agreed to let them distribute the small size only as clipart with the new version of office.  In turn the image links back to the same one on Fotolia so if they want a larger size or more extensive license they can buy it. 

I agreed because it was a small number of images and figure it will be very good exposure for my portfolio and for the site. 

Of course all this was before the subscription plan was announced and the daily Chinese water torture drip of unpleasant details....