Google, Microsoft and Starbucks are coming out to support gay marriage to win over young consumers, a marketing analyst believes.

Corporations are increasingly speaking out in favor of gay rights, in particular equal marriage rights for gay and lesbian couples.

Google's Legalize Love campaign is the latest example. In June, Kraft Foods, the parent company of Nabisco, ruffled the feathers of gay rights foes with an image of a rainbow themed Oreo cookie supporting Gay Pride posted on the brand's Facebook page. Foes held a 4-day protest outside the Minneapolis headquarters of General Mills after it came out against a proposed gay marriage ban in Minnesota. Coffee giant Starbucks is facing a boycott over its support for a gay marriage law in Washington state. Microsoft also supports the law.

On Wednesday, Christian conservative group AFA threatened to boycott Google's services and products for its global Legalize Love campaign, which fights discrimination in the workplace.

Speaking to MSBNC, Ian Johnson, founder and CEO of Out Now Consulting, said the stakes for corporations are much higher than the LGBT market, which is believed to be worth as much as $790 billion annually in the U.S. alone.

“They're not just marketing to the 15 million Americans who identify as gay or lesbian,” Johnson said. “They're marketing to the millions of people who support their work colleagues, their friends, their family.”

“As America is aging and Gen X and Y are moving into middle management, this is the core market,” Johnson said.

Younger Americans tend to support gay rights in higher numbers than older Americans.