A nonguerrilla thinks marketing is over once the sale is made. The guerrilla knows that's when marketing begins. The marketing you do subsequent to the sale is where the real profits are, so don't ignore customers once they hand over the cash. Selling to existing customers is easy and inexpensive.
Give yourself a challenge. The next time you acquire a new customer or client, make yourself add one more field to that person's file in your database. Call the category "Next Step." Without locking yourself into anything, try to generate an idea about what you might do for that person down the road. If the purchase involved carpet cleaning, you might want to call in a few weeks and offer to clean the person's upholstered furniture. Throw in a free spot cleaning for the carpets, just to show you like to keep your clients happy and their carpets looking good.
Excerpted from 303 Marketing Tips: Guaranteed To Boost Your Business