Today, I will opt out of any #MDPI email communication. Yet another email asking to peer review work that's clearly out of my expertise was the drop that filled the bucket.
Not to speak about the perpetuum mobile giving you vouchers for publishing your own work after you have reviewed something.
Not to speak about the insane amount of "special issues", one of which I was recently asked to co-edit while there's an ongoing one on exactly the same topic edited by a colleague.
No more words needed when you see the attached figure which I shamelessly stole from this fantastic article recommended by a friend.
https://paolocrosetto.wordpress.com/2021/04/12/is-mdpi-a-predatory-publisher/
Disclaimer: I'm not saying there's nothing wrong re: publishing culture in science in general but #MDPI is really pushing it here
