I think you need to think outside the box. You can definitely make 50k a month but someone just giving you ideas is not going to help you. Remember Ideas are just 1% execution is 99%. Find something you're passionate about. Find a problem that people have daily that can be solved.

But if you wan't ideas: E-Commerce is going to be really big over the net few years. Helping people increase their conversion rate will definitely make you over 50k a year if you can execute it right.