The short answer is that it doesn't.
IBM is an advertiser like any other, but we call them a sponsor because they've purchased ALL the ads on the site. They get so much prominence because that's precisely what they want -- presence.
That said, IBM is still an advertiser. SmartPlanet is fully owned and operated by CBS Interactive, CBS Corp.'s digital division. So we're completely editorially independent, and IBM has no say whatsoever in what we publish. We do write about IBM from time to time (they admittedly do some neat things), but we write about GE and Siemens and Cisco, too (they do neat things as well). From an editorial standpoint, we like a nice balance because we think it's appropriate. But again, IBM has no input here.
Where you see IBM advertisements and links -- along the right rail, for example -- they are labeled as such. We try to keep that divide clear, because we think it's important for both of us.
That said, there remains some confusion. IBM has a major corporate initiative called "A Smarter Planet" and we're named "SmartPlanet" -- it's easy to confuse the two, and many people do. But we've had this brand since 1999, so we're going to do our best to clarify that.
