U.S. vehicle-sales events tied to the holidays go into full swing each year between Christmas and New Year’s Day, one of the industry’s strongest periods for car buying.

But a trend indicates auto makers and dealers are keeping busy with such sales throughout the year, says Jon Swallen, Kantar Media’s senior vice president-research.

Until recently, “sale-a-thons” and the like typically were held around certain holidays, such as President’s Day and the Fourth of July.

“But they’ve become a year-round phenomenon,” Swallen says. “We have not seen a single week without an auto company or dealer somewhere holding a sale or advertising one.”

Hyped sales programs featuring particular brands of cars accounted for 33% of advertising by regional and metro dealer groups, he says at a recent J.D. Power and Associates conference.

National television spots continue to account for 50% of auto makers’ advertising. However, many TV ads now urge consumers to go to another medium: the Internet, especially auto maker and dealer social-media sites.

“We’re seeing more campaigns in which TV, print and website ads are directing consumers to Facebook sites,” Swallen says. “Tactics for online and offline integration continues to evolve.”

sfinlay@wardsauto.com