You have made the sale. Now that great, but selling more to a client at this stage would be expensive like starting over the entire process from the very first stage. In short it could also mean up – selling or cross selling where doing every small little thing for your client in order to maintain your relationship could add some benefits for you. You could do this by contacting them on regular basis, and providing value in such a way that the customer would first think of you when he or she needs the products and services.