Many Silicon Valley executives have outlined their opposition to the ballot measure, which Californians will vote on Tuesday. , and both of that company's founders have donated heavily to anti-Prop-8 efforts.

Still, it's rare for consumer-oriented companies to weigh in on potentially controversial topics. For Apple to publicly commit to a specific political stance is unusual, both for the company and for corporations on the whole since it runs the risk of alienating the percentage of its customer base that may not share those views. But, some argue those risks may be outweighed by the rewards.

Liz Loden, who heads cause-marketing firm iRainmakers, says that companies typically donate to multiple candidates or special interests. It's a way of ensuring the corporation keeps its business options open. "They want to promote conversation and dialogue on both sides," she said.

Taking a specific stance could certainly risk potential lines of revenue. But when a company takes a public stance on any issue, the first and most immediate risk comes not from the outside, but internally.

Take Microsoft, which has long enjoyed a reputation as a progressive employer. The software giant was one of the first major companies to provide domestic partner benefits and to include sexual orientation in its corporate nondiscrimination policy, it's lobbied against various local anti-gay initiatives and bills, and it has donated sponsorships or equipment to numerous lesbian, gay, bisexual, and transgender civil-rights and service organizations. But in 2005, the company from a Washington state bill that would have banned discrimination against gays and lesbians in housing, employment, and insurance. The reason, according to an e-mail Microsoft CEO Steve Ballmer sent, was the potential for divisiveness in the company.