neotoma

that might tempt them to buy comics they wouldn't otherwise have checked out

Most of DC comics for me, and THOR from Marvel (I learned that JMS was writing THOR via scans-daily).

I wouldn't have even HEARD about Agents of Atlas without it, and now I am a total Jeff Park fangirl.

and decide to start buying it again when they see it's getting good.

Yup, the various Xmen books go in cycles, depending on who is writing. I like to know when the titles get worth reading again.

I liked being able to discuss the comic that just came out.

And comics that were older than I am. The posting of old comics was one of the great things that I loved. It was a great resource.