By Gary M. Stern
FORTUNE – How many flash sale emails a week does it take to drive a customer bonkers? Ten? Twenty? Fifty? It looks like retailers are pressing their luck.
In a January study conducted online by YouGov, a whopping 75% of respondents of the 2,000 people surveyed online said that they are overwhelmed by retailer's emails and are turned off and resentful about receiving them. Given that many consumers don't want to be bombarded online, how are retailers responding to their backlash?
In 2012, top retailers sent out an average of 210 promotional emails to their customers, according to the Retail Mail Blog, which tracks email campaigns of leading companies. Consumers are suffering from email fatigue.
Disgruntled consumers can always unsubscribe, notes Simms Jenkins, who runs an Atlanta-based marketing company and is author of The Truth about Email Marketing. But even after an onslaught of unwanted emails, some still welcome that one message offering a two-for-one deal they can't live without.
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Email acceptance is often contingent on timing. Apple (AAPL) customers may ignore emails for six months until they want to buy a new iPad. Many consumers "emotionally unsubscribe until you deliver that email that gets them to buy," Jenkins says.
As many consumers gravitate toward mobile devices, email effectiveness depends on subject headings and "soft" sales, like offering benefits such as free shipping. Many retailers have also adopted targeted marketing tactics to avoid annoying customers to the point that they resent their brands.
Retailers need to spend more time sending "clear benefits to … subscribers" and avoid just selling, selling, selling. "If you forget the subscriber, you've done a poor job," Jenkins says. More
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