The moment following the initial sale with a new client is critical because it sets a precedent as to how often they should expect to hear from you. I recommend that immediately after you fulfill the first order, follow up with them with either a phone call or an email, or something that is only to them. You want to get feedback from them on how well you did, and you ought to invite them to be part of your contact list for additional emails or text messages. It can also prove beneficial to ask the new client what the best way to contact them is. Is it email, text message, a phone call, or a face-to-face visit with a sales rep? It shows the customer courtesy when you ask the best way to contact them.
When collecting their contact information, what is the best number they can be reached at? Another question you can ask at that point is how frequently they want to be contacted. That can give you an idea of whether this is a once-a-year type customer, once-a-quarter, etc.
The more they order, the more you should contact them. I believe it’s not offensive if they buy from you once a year, for you to contact them two or three times a year. It shows a lot of professionalism if you go the extra step and customize the information about that customer in your database instead of just putting them on your marketing list.
Additionally, a handwritten thank-you makes a bigger impact than a short message on the bottom of the invoice that says, “Thank you for your business.”
Make whatever you do memorable and different than what other companies do.