Lots of companies offer discounts and "free" stuff in exchange for posting a little ad on your Twitter or Facebook page. While it may be a good deal, you don't necessarily want to clutter up your social media feeds with a bunch of ads. The solution? Create junk accounts specifically for the purpose.
You can create an account with whatever name you like. When it comes time to sell a spot on your feed for a free coffee or app, just use the junk account you created instead of your primary one. While this might be a little disingenuous, you're still helping the company get the word out without annoying your friends.