I use to work in IT for a university that had members of their marketing team construct a little virtual campus in Second Life. They were paying real money for virtual real estate. It wasn't a whole lot when it comes to business expenses, but I think it was a few thousand a year. People were "visiting" it.

But Second Life was losing popularity by that point they were talking about just canceling/ditching the whole thing because it was no longer worth the marketing budget.