Search advertising appears to be recession proof, but the channel's success is directly correlated to display, according to a study by Specific Media.

By examining comScore data for its clients, Specific Media found that searches jump by 155 percent after consumers are exposed to display advertising. The largest impact display has on search comes in the travel and tourism industry, where searches increased by 274 percent after consumers saw travel ads on other websites.

Essentially, without display advertising to drive consumers to search engines, there's little use for SEM and SEO strategies.

"There is a connection between display and search ads," said David Hallerman, senior analyst at eMarketer. "Often it's not the search ad alone that gets consumers to act, but the context of all the marketing that preceded it."

While display is feeling the pinch along with other forms of interactive advertising, it will retain the second highest share of online ad spend over the next four years, just behind search, according to eMarketer. Even the search king itself, Google, will focus more on display to increase revenues amid the current recession.