Hey, glad to see my suggestion make it as pick of the week. What I like about this site is the Bookstore Mailing Lists & Library Mailing Lists. A real boon for small pressers.

These mailing lists are available for unlimited personal use – and now cost a lot less than other companies who charge you to rent their list for one time use.

I've worked on a few projects in the past where authors or presses wanted me to point them in the right direction in regards to marketing. Most bang for your buck here, by far.