Google has agreed to a series of audits on its video advertising metrics by the Media Rating Council (MRC), which serves as the effective watchdog for advertising measurement across platforms. MRC will audit three measurement companies that work with Google to measure how often and how much of their YouTube video ads are viewed by actual people.

Why they're doing this: Google doesn't want to lose the trust of ad buyers, especially on YouTube, which eMarketer estimates will add 20% in ad revenue in 2017. Because Google and Facebook have been bullish about releasing proprietary metrics to third-party data measurement companies, ad buyers have been wary about trusting the data they get from third-party vendors.

Why it matters: Google and Facebook have an effective "duopoly" over digital ad revenue, eating up more than 90% of all new ad dollars. In light of this, both companies have experienced heightened pressure to re-assure ad buyers about the quality of the data they release to third-party measurement companies. Earlier this month, Facebook agreed to an internal audit by MRC after they admitted to misreporting video viewing data to publishing partners.