Wall Street told investors YouTube TV will be a big hit due to Alphabet's dominant position in online video.
In addition, the new offering may signal a media power shift to broadcast channels from cable networks, according to the firms.
Alphabet announced its live streaming TV service will cost $35 per month for 40 channels and up to six accounts per family Tuesday.
Other internet live TV streaming services have reached modest levels of success so far. Dish Network's Sling TV has 1 million subscribers, AT&T's DirecTV Now has nearly 200,000 subscribers and Sony's PlayStation Vue has more than 100,000 subscribers, according to Jefferies' analyst Brian Fitzgerald.
"YouTube TV is an exciting development for Alphabet's crown jewel," Stifel's Scott Devitt wrote in a note to clients Tuesday. "Several services have a head start on developing digital skinny bundles (with more likely to join in the coming months / years), but YouTube is in an extraordinarily unique position with hundreds of millions of video viewers to potentially convert in the U.S. alone and over a billion users visiting the site every month globally."