Google's mobile search site shows some ads that promote a new notification service. Google's own ads feature a "subscribe" button that lets you "stay up to date on the latest deals, promotions, and updates from popular retailers". Basically, you'll get deals via text messages, just in time for Black Friday.
Tap the "subscribe" button and then you can text "join" to Google's SMS number: +1-646-665-2745. There are multiple alerts for phones, computers, TVs and more.