Progressive Corp., the fourth-largest U.S. auto insurer, is searching for the right message to attract customers to a product that tracks a person’s driving to set rates, Chief Executive Officer Glenn Renwick said.

Surveys of prospective Snapshot users have shown that “you get about 30 percent of people saying, ‘Yeah, why not?’; you get another 30 percent of people saying, ‘Maybe, I need to know more’; and you get about 40 percent of people saying, ‘No way in hell,'” Renwick said today on a conference call to discuss results at the Mayfield Village, Ohio-based company.

Progressive has sought to build acceptance for Snapshot after a campaign that Renwick called “very acceptable, but short of a breakout” in a letter to investors this week. The insurer has been counting on the technology to encourage safer habits behind the wheel and help identify the most valuable customers. Some have shunned the product, citing privacy concerns, Renwick said today.

Selling Snapshot has been “a bigger burden” than many in the company would have assumed given that it can lower customers’ rates, he said. “Intellectually, I kind of go ‘Why wouldn’t 100 percent of people take this option?'”

The insurer has increased the percentage of its customers at its direct channel who have tried Snapshot to about 35 percent from 20 percent two years ago, he said. Part of that gain has come from advertising how people who don’t take advantage of the product could be subsidizing others. In one “Rate Suckers” television spot, a spokeswoman says people who behave worse behind the wheel make “driving more expensive for the rest of us.”

‘Body Punching’

The base of premiums from the product total $1.8 billion, Progressive said in a report on second-quarter results. Premium revenue from individual clients was about $14.4 billion in 2012, a total that includes policies covering autos, motorcycles, watercraft and other vehicles. The direct channel includes customers who sign up by Internet, rather than through agents.

Progressive rose 2 cents to $25.66 at 4 p.m. in New York. Shares gained 22 percent this year, compared with the 31 percent rally in the 22-company Standard & Poor’s 500 Insurance Index.

Renwick said there is more work to be done on Snapshot.

“We’re body-punching here,” he said. “We’re trying to find the message that actually moves the needle. I think we now understand how significant a burden it is to try to educate consumers to do something that was not the natural buying or engagement process.”

Rodgers, Krasinski

Progressive has sought an edge over competitors as it fights for an increasing share of the $175 billion in annual U.S. auto insurance premiums. The company has gained scale along with the Geico unit of Warren Buffett’s Berkshire Hathaway Inc. in recent years by emphasizing low prices and selling directly to consumers over the Internet.

Advertising costs for auto insurers have ballooned in recent years, as carriers turned to celebrities including Aaron Rodgers and John Krasinski to pitch their products. Geico spent more than $1 billion in 2012, according to data compiled by SNL Financial. Allstate Corp. was No. 2 at $828.8 million, followed by State Farm Mutual Automobile Insurance Co. at $777.9 million and Progressive with $526 million, the data show.

Snapshot helped open a new front in the competition for customers. Progressive patented the device and has been asserting its intellectual property rights. It struck a deal in June with the United Services Automobile Association to license the technology.

Buffett said at Berkshire’s annual shareholders meeting in May that auto insurers are watching what Progressive does “with interest,” even though Geico has no plans to roll out a similar product. There are other ways to segment customers, he said.

Berkshire’s 82-year-old chairman and CEO said that he’s less likely to get in an accident than a 16-year-old male. Buffett quipped that’s because the younger man is “trying to impress the girls.”