I've gotten them elsewhere in the US, but can't speak to Europe. Usually they have strings attached; basically "work for us for a year or pay us this back". It's a good way to make the offer more attractive without it affecting the following year's budget, while also achieving a bit of risk management. Relocation usually stipulates the same thing; I know with a recent move and job change of my own, between signing bonus and relo costs, I probably would be looking at $50k if I walked away within a year, so yeah, they own me for that time. However I knew what I was getting into and so far am very happy there, so mutually beneficial.

I got one in Australia 10 years ago, but it was for a US company (one of the big Telcos that has a presence here). It's the only time I've ever heard of them here (for IT) though. I definitely get the impression it's more a US thing from how often I hear about them here and on reddit.