There has been a lot of talk lately about big brands like BMW and JCPenney trying to game the search listings by engaging in black hat techniques such as cloaking and link stuffing.
On the whole engaging in Black Hat SEO techniques might gain a brand a quick burst in the search rankings but over all the fall out is much greater. Getting banned from the Google search results is not work the small and temporary gain you might achieve.
Matt Cutts recently addressed a group of SEOs at Search Engine Strategies and explained that the search giant does in fact penalize big brands for engaging in Black Hat SEO.
Honestly I’m glad to see Google dealing with brands of all sizes the same.
The only true way for lasting results in Google and other search engines is to play by the rules (to an extent) and not push the envelope to the point of ripping.