The battle between streaming services and cable TV is about to get even more heated. By next year, more U.S. households will opt for an Amazon Prime membership over cable TV.

That's according to estimates from MorningStar, which found that the e-commerce giant has increasingly earned recognition for its original streaming content. That's not to say that members sign up solely for its entertainment services; Amazon Prime is mostly appealing for its vast array of products and speedy delivery.

Nearly 79 million U.S. households have a Prime membership, up from about 66 million at the end of 2016, according to the report. (Amazon doesn't release Prime subscription numbers so Morningstar's estimates are based on an analysis of Amazon's cash flow statement.) That number isn't too far off from the 90 million Americans expected to pay for cable TV this year, according to numbers from S&P Global.

Growing Prime memberships is vital for Amazon, and it'll likely see a boost thanks to its third annual Prime Day sale (read: Black Friday-like deals) starting today, July 10 at 9 P.M. (EST) and running through on July 12 at 3 A.M. (EST). Prime members spend an average of $1,300 annually compared with about $700 for non-members, according to Consumer Intelligence Research Partners. And with 80 percent of America's wealthiest households already paying for the service, according to Recode, Amazon has started offering discounts for those on government assistance.