“There is no one right frequency in e-mail marketing. Not only are business subscribers fickle; they are also moving in and out and through the sales and service cycle. Timing is just as important as content when it comes to engagement and lifetime value.
Don’t settle for “One frequency fits all.” E-mail is great at adjusting to subscriber needs. The technology and data you need are readily available.
Finding the right pace is worth time and effort. Nothing fatigues e-mail subscribers like excess frequency. It’s a key driver of both unsubscribe requests as well as complaints to the ISPs (clicks on the “report spam” button) and low inbox deliverability. Business professionals seem to have a lower tolerance than consumers, even when frequency is stated up front at the point of permission.
Instead of frequency, which is simply a measure of volume, think in terms of cadence — a measure of engagement“…read on
Balanced, rhythmic flow, as of poetry or oratory.
The measure or beat of movement, as in dancing or marching.
A falling inflection of the voice, as at the end of a sentence.
General inflection or modulation of the voice.
Music. A progression of chords moving to a harmonic close, point of rest, or sense of resolution.
I’m not sure how that works? but other than that, a useful article.