Expect to see more personal TV ads on YouTube in the near future. Google now lets advertisers run TV campaigns specifically targeted those viewers watching YouTube on a TV screen or media box.
TV ads on YouTube
Google has traditionally been operating with three ’device types’ for its advertisement, specifically mobile, tablet, and computer. The advertisement company wants to be a major force in TV, too, so it is now adding a fourth leg: TV.
What this means is that advertisers can now specifically target for example YouTube viewers interested in cars or video games, but only when these viewers use a TV device. The YouTube app on TVs has previously been showing ads designed for mobile devices. The new ‘TV’ device type includes Smart TV, Chromecast, game consoles, and media boxes such as Roku and Apple TV.
Google is an advertisement company and it has a strong position in search and other areas. However, its relevance in TV advertisement, which is dominated by TV networks, has historically been small. This initiative can be seen as the first strike that may eventually turn Google into a TV advertisement juggernaut.

As a user you can expect to start seeing TV ads that are more personal and tailored to the big screen. Advertisers will not be able to target you as an individual but they will be able to show targeted TV ads based on your search and usage patterns, and possibly do it for a lot less than through a conventional TV network / channel. TV ads have historically been pretty random - and expensive - but Google is hoping to change all of that. This is what some industry people like to call "addressable TV"
Google will initially show targeted TV ads on YouTube only but it may expand to other partners in the future. The company said that “on average, users watch over 180 million hours of YouTube on TV screens every day” (per June 2018). Google has previously said that a growing share of YouTube watching happens on a TV.