Patrick starts out with a post called Vote with your Dollar, where he talked about BioWare's Jade Empire, where two of the male characters had bisexual romance options. His argument -- or, rather, his boss' argument -- was that it wasn't cost effective because people didn't buy it for the romance. Kameron Hurley responded in Gay, Lesbian & Bi Characters in Games by arguing that "if any gaming company wanted to expand their sales, they'd look at ways to expand their audience." (This, by the way, is echoed by BetaCandy in the post Game Marketing: Giving the Audience What it Wants.) Patrick responds with Vote with your Dollar, Redux where he expands upon how cost affects what to put into games.
Anyway, it's interesting stuff. There's definitely more that can be said on this issue (on Patrick's blog I've asked about what kind of marketing has been done so we'll see what he says.