This is a classic business strategy question, actually: should you focus, or should you diversify? There are obvious benefits to each, however, and at some level, what's best for you depends on your personality as much as your business area.

Many companies fail because of a lack of focus, so one thing to consider is whether you have the ability to really launch and put the ongoing effort into making more than one business successful. Shoes, toys and guitars are pretty discrete businesses and I can't think of a retailer that focuses on all three simultaneously, which might be a warning that you're a bit too diversified with these.

This is why most people have one major when they go through college, actually. They might well be interested in more than one area, but focusing the majority of your attention on a single area, be it shoes or foreign policy :-), produces better long-term results.

On the other hand, online sites are different, and I too have a number of different domains hosting different businesses, some of which get lots of my attention and others of which chug along for weeks or even months on end without my peeking to see how they're doing, so I definitely understand the lure and value of diverse income streams.

To me the ultimate question is whether you have the ability to manage three different stores simultaneously. I know it can be done, I have friends who are very successful in the affiliate space with two, three, ten or even dozens of different affiliate stores. Each individual store tends to be pretty similar to the others, but that's not necessarily a problem if you're experimenting, learning what works best, and then applying it to your other shops.

So I'll wrap up my answer with a question: do you prefer to focus on one thing and make it the very best, or do you prefer to juggle multiple things simultaneously, comfortable with the idea that no one of those will be the very, very best because collectively they'll all be doing well?