Stupid Question [stupid because I should know this]: If facebook shows 4 advertisements on a page, is that counted as 4 impressions in the "impressions" metric?

Stupid Question [stupid because I should know this]: If facebook shows 4 advertisements on a page, is that counted as 4 impressions in the "impressions" metric? Has there been any effort to normalize the effect of showing ads [I don't think I've ever seen a google page or search with 3, let alone 4 ads]? Theoretically, a person could load a page with a ton of ads and artificially boost the impression measure ...