If you had or have a very low monthly income, possibly from benefits, and very poor credit, and were unexpectedly given £15k, what would you do with it, on the basis that you most likely wouldn't be able to get a mortgage, and this windfall isn't going to (or at least likely to) ever happen again.
I actually don't think it would be a good idea to 'spend it'. With the exception of perhaps treating yourself to a nice meal or some new clothes if you haven't been able to do that for a very long time, I'd be very interested to know how people would invest it, or how they would make more money from it. Is it a viable amount to start a relatively successful business with perhaps? Does that depend on the business? 