Stefan Pollard at Email Labs has written a good article that looks at the factors that dictate how often you should send marketing emails.
Clearly, finding the right frequency for emails is vital - emailing customers too often can put them off, while not emailing often enough can cause the same problems.
Stefan outlines three strategies for determining the correct frequency:
1. Understand who controls frequency
Stefan points out that customers are becoming savvier when managing inboxes, and many will delete, unsubscribe from, or report as spam any emails they may find annoying.
In addition, customers will often consider annoying emails as spam, even if they have a relationship with that company. In a DoubleClick survey, 49% of respondents classified spam as '"email from a company I have done business with but that comes too frequently''.
This means that customers are the ones who should be determining the frequency of emails they receive.
2. Listen to customer feedback
Take note of what people are saying when they unsubscribe. They may be telling you they are receiving too many emails, or that the ones they receive are irrelevant to them.
Give customers a chance to tell you how many emails, and what kind of emails they are happy to receive, either when they opt-in in the first place, or through the emails you are sending them. The more relevant the messages you send, the more frequently you can send them.
3. Respect your subscribers' choices
You should stick to your promises about email frequency, even if you have a deal you know your customers will love. While many will forgive one or two extra emails, it could be the tipping point for others.
"Instead of sneaking in another mailing, refine your list description that specifies a general number but allows you to reserve the right to send relevant messages between regular scheduled mailings.
"Specify a range of mailings in a given time rather than a specific number, but be as realistic in your expectations as you can."
The article also warns against not sending emails often enough, as customers may forget they subscribed after a while and treat your email as spam. He recommends that customers should be emailed at least monthly.
How often should you email your customers?