Facebook and Omniture, the Web analytics software maker, said Wednesday they are working together to help companies use the world’s largest social network as a marketing channel.

Using Omniture’s products, companies will be able to measure how effective their ads are on Facebook. They will also be able to use Omniture’s search engine marketing management tool to buy Facebook ads. And they will be able to compare how well their ad campaigns do on Facebook compared with other outlets.

EMarketer analyst Debra Aho Williamson said the deal is a “really big move” because many large online marketers use Omniture on a regular basis.

“Marketers have been so interested in Facebook, but frustrated by the lack of analytics that Facebook is providing them,” she said.

The partnership with Omniture, which Adobe Systems Inc. bought last fall for $1.8 billion, will boost ad spending on Facebook, she added. EMarketer expects worldwide ad spending on Facebook to hit $605 million this year. That would be a 39 percent increase from 2009.

“If it’s hard to understand how effective advertising is, companies are less likely to do it,” Williamson said.

Wednesday’s announcement expands a partnership Facebook and Omniture started last year.