Some 35% of those with kids younger than six in their household are at least somewhat interested

Once, coupons and offers delivered to mobile phones were used mostly by early-adopters of smartphones, predominantly young males.

No longer. Today, the demographic embracing mobile coupons is the same one most likely to be clipping them offline: parents with young children.

A study conducted by Harris Interactive found adults with children at home are more likely to be interested in text alerts about sales and promotions than those with no kids at home. Of people with kids younger than 6 in their household, 35% are at least somewhat interested in getting opt-in text alerts from favorite businesses, compared to 32% of households with older kids and 25% of homes with no children. (The study, conducted in May with 2,000 adults, does not distinguish between childless adults and empty-nesters.)

That's a big shift from last year when the same study found mostly young males were interested in receiving marketing alerts on their phones, which coincided with the demographic most quickly adopting smartphones -- young, affluent males. Mobile marketing firm Placecast funded the Harris studies both years.

The new data also show that parents of youngsters are also more likely to sign up and redeem coupons via e-mail, online or through services such as Groupon. While the difference is less dramatic, it's the same group most likely to clip and redeem coupons from fliers, mailers or newspapers.

In the year between studies, the balance has tilted away from men, as adoption of smartphones such as the iPhone and various Android devices has become more popular. Most receptive to mobile offers are still young adults 18-34, and women's interest has grown year over year.

"Men might do these things first, but women will take it over because they remain the primary shoppers," said Kathryn Koegel, a Primary Impact consultant involved with the study. "Especially when there are children, it all becomes about convenience."

Forrester mobile analyst Julie Ask is less convinced that there's any correlation with having children, just that those interested in mobile coupons are under 40.

"From our data, it doesn't matter if you have kids or not, it's just that they're young," she said of audiences with affinity to mobile coupons. "Parents with young kids are probably also younger."

A 2009 Forrester study on mobile coupons found that 70% of respondents younger than 39 receive coupons or promotions on their phones at least monthly.