How often should an online store email its list?

Start from how often a customer could reasonably buy from you. A store selling coffee, skincare or pet food has customers who reorder every few weeks, and weekly contact fits naturally into that rhythm. A store selling furniture or mattresses has customers who buy once every several years, and the same frequency reads as noise.

The second input is how much genuinely changes. A store with new arrivals every week has material for weekly sending. A store with a fixed range and two seasons does not, and manufacturing reasons to email produces exactly the sort of message people unsubscribe from.

The third is the season. Almost every store has periods where more frequent contact is welcome, because customers are actively shopping, and periods where it is not. Planning frequency by quarter rather than as a fixed weekly rule handles that.

So the honest answer is a range rather than a number, and the way to find yours is to move within that range deliberately and watch what happens.

The best way to send more without annoying more people is to send different things to different groups. A store sending one campaign a week to everybody can move to three a week where each goes to a third of the list, and the individual subscriber's experience does not change.

Segment by behaviour first: recent buyers, browsers who have not bought, lapsed customers, subscribers who have never purchased. Each of those needs a different message anyway, and separating them makes the content better as well as the frequency safer.

Segment by engagement second. Your most engaged subscribers can take more contact than the rest and will reward it. Your least engaged should receive less, both because they are not reading and because sending to them affects whether the rest of your mail reaches the inbox.

Then let preference do some of the work. Offering a choice of a weekly digest or occasional highlights retains people who would otherwise unsubscribe, and it tells you something useful about the list.

Unsubscribe rate per campaign is the most direct feedback. A rate that climbs as you add sends is the list telling you where its ceiling is, and it does so before the damage is permanent.

Spam complaints matter more than unsubscribes even though they are rarer, because they affect whether future mail is delivered at all. A rising complaint rate after a frequency increase is a stop signal rather than a metric to monitor.

Inbox placement is the one most stores never look at. Sending more mail to people who do not engage teaches filters to treat your mail as unwanted, and the first symptom is not a complaint but a quiet fall in opens across the whole list.

Revenue per subscriber over a period is the measure that decides whether the change was worth it. Total campaign revenue almost always rises with frequency in the short term, so use revenue per subscriber and watch it alongside list size, since a list shrinking faster than revenue grows is a bad trade.

Cap total contact per person across campaigns and flows together. Somebody in a welcome sequence, an abandoned cart sequence and a weekly campaign can receive several messages in two days without anyone intending it, and the flows are usually excluded from the frequency count.

Suppress the obvious. Recent buyers should not receive the campaign for the product they bought yesterday. People in a returns process should not receive a promotion. Subscribers who have not opened anything in months should be in a re-engagement path rather than in the regular schedule.

Send from a stable identity with authentication configured properly, and keep transactional mail separate so it is not affected by campaign reputation.

And keep the content worth the interruption. The most reliable way to send more often without cost is for the emails to be genuinely useful: how to choose, how to care for it, what is new and why it exists. Stores that can only write promotions hit their frequency ceiling early.