GEO names are great. I think this one is a nice one as it's very popular with the lobster-faced British tourists (when the economy is ok).
It's going to be tough though because it will be hard for someone to focus on both Tenerife and Lanzarote and everything else there. Could work to your advantage or against imho. Hard to say.
I think you have a winner! 'Canary Islands' encompasses the whole group of islands of this very popular European(not only the Brits)tourist destination. The best known islands being Tenerife, Gran Canaria, Fuerteventura and Lanzarote although there are many more smaller 'escapes'.
I for one would have loved to have picked this up for reg fee and I'm sure many others here would have too........Good luck, although I don't think you need it with this one.