You should ask this question at least twice a year. Your clients will likely always have suggestions for you. From friendly reminders to more advanced services, your clients may end up needing more than you first expected. Thus, you may find that this little question can provide a lot of revenue throughout the years.
2. “Is There Anything Else IT-related That Your Company Needs Help With?”
You should be asking this question often as well. Perhaps they've been meaning to ask you about certain issues, but they constantly forget to ask while you're there. By asking this question you are likely to get even more business from good clients.
3. “Do You Know Anyone Else Such as Business Associates, Friends, Family Members in the Greater Area That Could Use Some Help With Their Computer-related Problems?”
A lot of people will not refer you no matter how good you are unless you ask them. They may assume that you already have a full load or that you might not be willing to drive to another part of the city for work. Always see if they have any ideas for referrals.
For more on requesting referrals from clients and training them to know when you might be of service, read the full article (link above).
Added by Joshua Feinberg