Over 6000.
We use Cha Ching, and not only does it count your customers, it tells you which have spent the most, gives the cleaning frequencies of each and every customer, and lists all that was cleaned, and has a place to make notes about the dog's name, etc. It also has the average of every customers' jobs, so you know what your average ticket brings in each month.
It will break it down daily, weekly, bi-weekly, etc.
That is just a few of the things Cha Ching does.