I think this is a very generalized question. Without knowing the specifics, such industry and product or service you are offering, it would be hard to answer this. Generally speaking, a lot would depend on the team you have in place. You have to visualize the effort required for each new business model and project and envision how this effort would be executed and by whom. If you have sufficient resources and scalability to afford an expansion, then there is not reason to hold back.

When I started C&M Group, I faced this problem head on. I started doing strategy consulting, product, SEO, business development, marketing, etc. to do everything "under the roof". Guess what? It didn't work. My suggestion would stick to what you do best, and try to leverage products or services around that. The last thing you want to do is have 10 different projects and services and trying to figure out how to add additional revenue. This will simply cause you burn out. Focus on something that has a need, validate it, and push it in the market.

I realize this is an aged question, however I'd be happy to talk to you about this. I work with a lot of founders and startups in this area.