According to a new survey of more than 1,000 U.S. shoppers from customer targeting technology provider First Insight, the average consumer subscribes to 2.3 retailer email lists and receives 13.1 emails a week from these lists.

On the high end, 6% of respondents receive 40 or more emails a week. Two-thirds of the consumers who receive six or more emails a week said it was “too many.” Six appears to be the magic number for annoying customers with weekly emails – only 21% of shoppers who receive five emails per week think it’s too many.

However, retailers may want to consider cutting off weekly emails at a number far lower than five. Sixty-one percent of consumers say that their favorite retailers only send them one or two emails a week.