I'll give an example and a TL;DR TL;DR have it where we can get notifications whenever someone lists on a marketplace Example: X person listed in X category and has X game that I want, but it is out of my budget. Have it where there is a button to send email notifications to notify a person whether or not a new listing is active and is within X - X range so that is in my budget. If you want me to explain more let me know, I don't know how to plainly explain it but this would be a nice addition to the marketplace.