Google announced the launch of the Browser Size analysis tool in Google Analytics, under the In-Page Analytics report. The tool shades the portions of a page that are "below the fold," and shows you what percentage of users are seeing how much of the page.
"What is actually 'above the fold' on a web page is a significant factor to conversion rates," says Gaal Yahas from Google's Analytics team. "If visitors have to scroll to see an 'add to cart' button, or some other critical element, they may never get around to it. Analyzing the percentage of visitors for whom page elements fall beneath the fold or off to one side is difficult, so we've created a visualization that lets you quickly determine which portions of your page are visible to which percentages of visitors."
This may prove to be a helpful SEO tool, as well, considering Google's recent "Above the Fold" algrorithm update, which penalizes pages with too many ads above the fold. In January, Google's Matt Cutts wrote, "We understand that placing ads above-the-fold is quite common for many websites; these ads often perform well and help publishers monetize online content. This algorithmic change does not affect sites who place ads above-the-fold to a normal degree, but affects sites that go much further to load the top of the page with ads to an excessive degree or that make it hard to find the actual original content on the page. This new algorithmic improvement tends to impact sites where there is only a small amount of visible content above-the-fold or relevant content is persistently pushed down by large blocks of ads."
In fact, in that post on Google's Webmaster Central blog, Google suggested using the Browser Size tool, which at that point was just part of Google Labs. That version will be sunsetting in a month, and you'll have to use Google Analytics.
This seems to be becoming a trend with site optimization tools from Google. Google's just building them into Google Analytics. Last week, Google announced the addition of Content Experiments in Google Analytics, which is taking the place of Google's Website Optimizer:
Both the Browser Size tool and the Content Experiments tool are rolling out to Google Analytics users over the next few weeks.