The best thing you can do for a business is help them build a list. Just keeping in contact with their customers on regular basis, offering special deals and upsells does wonders. All the things IM do, brick and mortar businesses need these things too.
--autoresponder on website
--newsletter (online version)
--update current website, make it client oriented.
--Facebook Fan Page
--Twitter
--Business Directories: Yelp, Merchant Circle, etc
--Press releases
--Article writing
--online commercials (videos

)
Offline stuff works great too.
--A physical newsletter. (the best) Client pays for this.
--Teaching the business how to answer the phone.
--Teaching the sales clerks to up sell when a customer is making a purchase. Fast food restaurants have this down cold.
All these little things mean a lot to a business. Check the download section
for stuff from AP. He was d*ck, but his stuff is golden. If you can't find it. PM me.
T