Assuming that you delivered on the promises you made when starting work with your customers, you will continue to keep them happy between projects the same way you won them in the first place…….by being helpful, professional and accessible.
My suggestion is dont just send out a questionnaire or a sporadic newsletter as part of your marketing activity. Make time and effort to actually see customers even if they aren’t actually giving you “live” work. Maybe even ask for an in-depth client review meeting where both parties can re establish the face to face dialogue and properly go over past work and possible upcoming opportunities. Maybe audit any recent activity or even review what you have done (after all even the BBC reviews their website every 18 months!).
I would think that getting repeat business from customers would be a requirement as a minimum, but keep in mind recommendations that they may give to their contacts as well. In Bath Marketing’s opinion, you must give yourself the best chance to expand with your clients as they expand so staying in touch and the methods for doing so, should be something you have a plan for in your marketing plan.
However, always do an internal review before this sort of meeting so that you can assess the real monetary value of your client to your organisation (not all clients are actually profitable in my experience!) as well as the possible cross selling opportunities. My old MD used to really push KIT (keep in touch) and I have to say that I fully agree with him!