Google just removed today the limit of 3 ads per page, a very old policy that keep publishers to have many ads on their pages. This does not mean that publishers can have more ads, as the rule “pages with more advertising than publisher-provided content” still exists.
In a statement to Marketing Land, a Google spokesperson just confirmed this policy changed: “We’re always fine tuning our policies to make sure they reflect the current environment. In one recent change, we stopped limiting the number of AdSense ads that could appear on a page and instead now look at the overall balance of content and ads on a page. We think this better takes into account experiences like infinite scrolling and in-stream video. As always, we encourage publishers to keep the user experience in mind and require they have more original content than ads on the page. “
Google have now rules that are not so specific. Before there was a limit up to 3 ad units, 3 link units, and 2 search boxes. Now Google is giving more freedom to publishers to insert more ads according to the density of their pages.