Estimating a celebrity's net worth usually involves some creative guesswork, but in Gene Simmons' case, we actually have a pretty decent ballpark figure. According to Inc., Simmons is worth a whopping $300 million, but don't think for a second that all that money comes from playing rock music in a costume. Kiss songs are popular, but they're not that popular. To supplement his income from his day job, the business-savvy Simmons is a serial entrepreneur who's operated, among other things, a sports team, a restaurant chain, and a financial company. He's also a successful author, reality show star, and even a business lecturer.

Unsurprisingly, Simmons has also taken his business acumen to his mothership. As the man himself puts it, "I like being part of a rock and roll band, but I love being part of a rock and roll brand." In fact, the whole Kiss bad boy image is carefully cultivated to achieve precisely that, with remarkable success. The band's name has been licensed to a ridiculous 3,000 product categories — not products but product categories. From condoms to credit cards and lunch boxes, imagine a product, and there's a decent chance you can grab a Kiss-themed version of it. As a result, the Kiss brand is estimated to be worth nearly $1 billion. That's plenty of incentive to keep applying that greasepaint and climbing in those cumbersome boots.