AOL's third annual "Email Addiction" survey asked more than 4000 Americans over 13 about their email habits, and a found that users checked email at night, on vacation, while at work and often had multiple accounts, representing an opportunity for brands to benefit from that frequency with the right message.

One in three users say they know someone addicted to email, with the most likely suspect being a friend (18%), a spouse or significant other (7%)--and even a boss (4%).

When it comes to the addicts themselves, they tend to skew female (16% of women considered themselves email addicts compared to 13% of men), and younger (19% of users 13-34 considered themselves addicted, compared to 10% of users over 34).

But even Americans who didn't consider themselves email addicts indicated the pervasiveness of email in their daily lives. For example, about half (52%) of all email users have two or three accounts, while 22% have four or more.

And users don't let work stop them from checking their personal email--as some 60% of those employed outside the home check their personal email at work. Users checked their personal email an average of three times per day, and most of them (72%) say they don't feel guilty about it.

Email is infringing upon both sleep and vacation as illustrated by a number of statistics, but both factors pose possible benefits for advertisers. Some 40% of email users have checked their mail in the middle of the night, with a higher ratio of men (44%) to women (36%)--highlighting an opportunity for pharmaceutical companies peddling sleep aids to choose display or banner ads in email as a possible ad channel.

Next, some 38% of users say it is very or somewhat important that they have access to email when planning a vacation--and a majority of users (83%) check their email at least once a day while on vacation. Behaviorally targeting trip planners with relevant email ads before and during their trip could serve as a supplemental marketing strategy for local attractions and businesses.

This news story is important. I recommend that everyone read it.