Hi Wayne
Any sort of contact is good - its the non contact that does the damage to a CC business. I would send the ones who havent used you for 12 months a letter, and also the ones who havent used you for 18 months at the same time.
Keep getting in to a cycle of sending the ones who havent used you for a set period of time i.e. 6 months, 12 months, 18 months, 2 yrs, etc etc all the way up to 5yrs. This way your clients who need reminding will get reminder letters - every 6 months. If they havent responded after 5yrs (of getting a letter every 6 months) then this usually means they dont want to use you. But dont give up on this, we have clients coming back after 5 or 6yrs, even though we gave up sending them reminder letters.
Remember, even existing clients like an offer (because you 'value' /want to look after them) - but this isnt the most critical part, the actual contact is.
As an example, on this months letter we got back £2,000.00, which isnt unusual and is about average. So its a real no brainer sending them out every month. Obviously this is only one part of our marketing income - there is the internet, van, associated trades, retailers, referrals etc etc etc.
This is the important bit -
you are not sending out to the SAME people every month (only the ones who havent used you for a set period of time - which changes every month as time revolves forward obviously!). So you always have different clients your sending to in between the 6 monthly contacts.
Sorry if the above sounds confusing - it does to me! But its a very straightforward easy process.
This is what we sent:
http://clean-pro.co.uk/May_Letter.jpg Ok its not the most exciting or even different thing, but its...the contact that counts! Ignore the date as it is a screenshot of Word and the date has auto updated on opening.
Here is a shortish video on why marketing to existing clients is so important - if you havent guessed already!!
http://www.youtube.com/watch?v=wG9_IRAAk60 This is not an advert for cleaners mate by the way.