Just curious, do you find the websites of small/medium-sized businesses are predominantly PHP/Rails/Django or are you seeing ASP.Net and Java? The reason I ask is because if you market yourself as simply a problem-solver you'll need to be proficient in a wide range of programming languages.
I see mostly WordPress, Shopify, and a smattering of Rails (but Rails may be because that's one of my favorite tools). I've never seen ASP or Java out in the wild, but I'm 1 man who doesn't focus on those techs.
PHP dominates the web, but I'm sure there is plenty of business elsewhere. The internet is pretty vast - some of my clients are in niches you've likely never heard of. If you were working in particular industries, you might see ASP/Java more often, depending on who the major players are there.
Oh, and I'd shy away from marketing yourself as a generic "problem solver". Try to find a more specific problem to solve (i.e. "I boost sales for eLearning websites by improving website speed"), and focus on that instead.
