That's because the airline discovered, in a test study it conducted with ad-serving firm DoubleClick, that rather than acting right away by clicking through on an ad, consumers bought tickets on Continental.com up to a month after they saw an ad.
The highest point of sales was two weeks after the ad was served-with a 225% increase in conversion over the control group. And a month after consumers saw the ad, they were still buying tickets at a rate of 210% over a control group. One hour after the ad was viewed, sales conversion was only 129% over the control, and one day later, it was 204% higher.
The results can change the way high-ticket and considered purchases like air tickets are sold online, said Colleen Aranda, manager of interactive marketing, Continental. "Buying airline travel isn't usually an impulse buy," she said. "So just counting on the direct action after someone sees an ad isn't realistic."
Delayed response-or "viewthrough rate," which is taking an action some time after an ad is served-is something marketers always knew occurred, but couldn't prove. Most rely on clickthroughs, how many consumers immediately view an ad when it is served, as a measure of online ad effectiveness. DoubleClick and competitor Advertising.com have measured viewthrough for some time, but marketing strategy does not commonly take this metric into consideration.
"What's different is that long-term response can now be measurable," said David Hallerman, senior analyst, eMarketer.
In the Continental promotion, 67.5% of sales conversions can be attributed to online ads, according to DoubleClick. Registrations for Continental's e-mail newsletters, which were also measured in the study, tended to occur soon after consumers saw the ad. After an hour, there was a 364% uptick over the control, 420% after one day, 377% after 14 days and 211% after a month.
"People are more likely to take an action for something like a registration after seeing an ad," said Kathryn Koegel, director-research & industry development. "But something like a purchase has a longer window of response."
The ad campaign, which occurred in February, reached 3.6 million unique users: 2.1 million were in the exposed group, and 1.5 million were in the control.
The number of times consumers saw the ad was not measured. The findings also didn't uncover which sales came from new customers.
For Continental, the conclusions allow Ms. Aranda to make a better case for spending money online. "And it opens the door for us to include some brand messaging in our mix along with a direct action that just talks about booking on Continental.com," she said.