The webinar discussed the upcoming change to using viewable impressions as the standard metric for digital advertising. Panelists included executives from an advertising technology company. They noted viewable impressions will lead to a 50% drop in ad impressions but higher CPMs for premium publishers. Operational challenges for advertisers and publishers were identified in implementing the new standard. The key takeaways emphasized viewable impressions will increase advertiser ROI and advertiser demand, benefiting premium publishers.