I am looking for an area to begin making programs in. Android / iOS store is overpopulated and is hard to make an impact. Web apps are an option but I'm also looking for something where I can generate revenue.

Windows store is an interesting option for me because of the increasing sales of the surface tablets increasing the Windows user base. Are these tablet users looking to download windows apps? Or are they just using the web and using it like a desktop. (not meant to be answered, just a question).

My question is: is it worth the time and effort to learn Windows app development?