youtube to mp3 monetization

I am considering to get my own youtube to mp3 site. i know there are alot of them out there, but i want my own for a specific niche as a branding tool.
i.e-> i have a blog that will seen traffic to this utube2mp3 type site where the user will download the mp3, but the script will also tag the mp3 with a image and the logo as a tool of branding. so that the user will remember to comeback to this specific site.

anyways the question i am asking is, when a user goes to one of these sites how is it monetized, or how could i get revenue from each download

Content lock the download page with a content locker.

content locker, banner adsor ad.fly like service.

there are tons of free sites and software applications that do this

you can try this one https://ytformp3.com free youtube to mp3 conversion site