Absolutely. This is a great way to make money on YouTube, as artists will jump at the chance to grab a free beat. Then, once they upload their video to YouTube you can earn from it, the same way you would with any beats you have sold.
If monetizing free beats, it is recommended that you don't advertise/list them as royalty-free, as this will be contradicted when a claim is placed on the user's video. If a claim is disputed on the basis that the video owner received the beat as a royalty-free download, we will release this claim. This includes posting them on royalty free websites like Motion Array, Epidemic Sound, Soundstripe, Audioblocks, etc.
Find out how to give away free downloads here