It’s sometimes hard to comprehend just how much people love t-shirts. And with the right niche, marketing, and tools, you can create an online t-shirt business that makes you extra money online while you sleep. (Even Bloomberg and Forbes feature stories from entrepreneurs who've done just that.) Services like TeeSpring make it easier than ever to create a t-shirt drop-shipping business where they handle the sales, printing, and shipping, and you’re only responsible for design and marketing. Or you can even buy into well-established franchise businesses like Rhea Lana that sell fashionable, affordable kids clothing and get the backing of a proven organization to fuel your online sales. For more tips, check out this simple guide to launching and marketing an online clothing store by my friends over at Selz.