If you follow any celebrities on Twitter, you may notice them tweeting about brands or products every so often. Granted, most are not actual spokespeople for the product itself, but that doesn't mean they're not cashing in for the mention.

When it comes to brands and celebs, Twitter deals are mutually beneficial. Businesses are well aware of the influence the rich and famous have on Twitter, with some bigger celebrity names having a follower base of millions. And most companies are more than willing to pay up for an endorsement, knowing people frequenty take commercial advice – for better or worse – from actors, singers, models, and yes, even reality stars. One positive Twitter mention from Kim Kardashian to her 17 million followers, for example, brings huge exposure to a brand. And the fee she may charge, which is speculated to be around $20,000 per tweet, is well worth it given the long-term monetary return on that investment.

So which celebrities charge the most? You may be surprised. And the next time you see a celebrity tweeting about a product, you may wonder just how genuine that sentiment is!