Over six out of 10 U.S. CMOs and senior marketing professionals surveyed said that digital tactics, including mobile, contributed more than one-quarter of their agency marketing, according to a study conducted by Zoomerang for Sapient in July 2008, eMarketer reported.

The study also found the importance of digital marketing was growing. About half (45 percent) of respondents had either switched or planned to switch agencies during the next 12 months for more access to digital expertise. Nearly eight out of 10 said agencies' interactive and digital aptitude was either “important” or “very important”.

The sample of the study was fewer than 100, which indicates the results are most useful in a directional sense. However, the amount of digital marketing (generally over 25%) seemed pretty high. Digital ad spending growth, compared with other media, remains high, but it still makes up less than 10 percent of the overall U.S. ad spending, eMarketer reported.

In the survey, Sapient asked respondents about marketing activity instead of marketing spending. As e-mail is relatively low-cost, it can account for a great deal of marketing activity relative to its cost, according to eMarketer.

“Some of the marketing professionals surveyed could have been including e-commerce initiatives in their estimates,” said Gail Scibelli, vice president at Sapient.