It’s interesting how when we think about online advertising, we only think about text ads in search result pages and easily ignored display ads throughout the web. Google is also offering a more engaging form of advertising that makes use of javascript to create an engaging experience for the user: Engagement ads.
Engagement ads appear as a display ad at first, but after the user hovers their mouse over them for 2 seconds, it can expand into a larger ad or a lightbox filled with rich content to engage the user. Inside the lightbox, you can have anything from your youtube masthead to an interactive game.
Google claims users are ten times more likely to engage with these ads than to click on a standard display ad and users spend twice as much time engaging with them.