I develop an online classified advertising web/mobile service. Right now users don't have to be logged in to place an ad. It is enough to use a valid email address. Having an account has other benefits now; it allows you to send and receive messages and keep track of everything you have posted.
Lately, I have considered requiring users to be logged in because it will be easier to program. Are there other advantages or disadvantages?
One possible advantage of doing so would be that we can track and know the users' details and prevent spam ads.