Over at SEOBook, Aaron Wall has a prescient quote from the Google Founders in 1998: “We expect that advertising funded search engines will be inherently biased towards the advertisers and away from the needs of consumers.” He then goes on to chronicle how Adwords ads are expanding both in complexity and size on organic search results pages, while the cues indicating the listings are ads are becoming increasingly subtle. I would argue that the cues are already essentially zero for most users.
For most monitors, the default color, contrast, and saturation settings are pretty messed up. Fortunately, we humans tend to be pretty good at overlooking them. Indeed, until I started doing some front-end web development projects, I had no idea how off the colors were on my HP monitor. I’ve probably spent hundreds of hours using this monitor, and hadn’t noticed the issue. At Google I’m sure they buy expensive monitors, and lots of Googlers have Macs with precalibrated, integrated screens of very high quality. Additionally, most designers spend time calibrating their displays and are trained to be very sensitive to subtle color variation. To the end user who never increased the contrast from its default setting, has a white point that’s a bit yellow, etc, the ads may appear as white or almost white–indistinguishable from the now identically styled organic links below it. In fact, it wouldn’t surprise me if their A/B testing on the background color of ads is actually inadvertently finding colors that look particularly close to white on the average miscalibrated monitor.
In fairness to Google, Bing is just as bad if not worse. I spent about half an hour doing everything in my power to calibrate my HP monitor’s colors, and still their extremely light blue background for ads was almost invisible. (And only somewhat noticeable on my iMac’s built in display.)