A corporate trend started in the mid-'90s, due to two factors:
1. aging hippies cum corporate executives who feel the need to reconcile their present positions with their beliefs
2. a revitalized consumer protection movement, a la Ralph Nader
To adhere to the standard of social responsibity, it seems that so-called "progressive" companies like Ben and Jerry's, Starbucks, Working Assets and Greenpeace*; as well as companies with notoriously bad track records, notably oil companies and HMOs; must spend millions of dollars on advertising and public relations to convince customers of their deep down goodness. It is more important to do this than to quietly spend an equal or even lesser amount of money to actually do some good in the world.
*yes Greenpeace is a corporation, not a non-profit, employing some of the most ruthless downsizing consultants in the business and cutting edge anti-competitive practices