These are two online Business ideas can be done besides job. Many people are doing these businesses beside their job and earning well. Though sometimes it needs extra time but its still possible to continue with these.
An eBay Store
You can start your small business today by registering under eBay. This home-based business idea I think is great for aspiring entrepreneurs to use as a jumping-off point is starting an eBay store. The site is intuitive. And the cost is very cheap. Start one on which you have great knowledge, and search deals. Suppose you have huge knowledge on cars, you should start buying and selling small accessories that you would buy for yourself.
Build online niche communities
Facebook, Twitter, Linkedin can help you build your own niche communities by the way of liking. You can aggregate individuals who have common likings and interests. You can start selling your product here. Its a nice idea, and all you need to do is to give continuous effort.