Online shoppers will begin furiously refreshing their computers tonight when Amazon.com Inc.'s (AMZN) Prime Day gets under way tonight at 9 p.m. EDT. (The start is three hours before official Prime Day.) As usual, the shopping bonanza will be headlined by electronics with the focus on Amazon's own brands like the Kindle, Amazon Audible, and the new Amazon Fire television. However, after Amazon's recent splurge into the grocery market, the e-commerce giant may use the buzz to promote another new business. "Coming off the Whole Foods' press coverage, [Amazon] can leverage shoppers' interest in this deal," Meaghan Werle of Kantar Retail told CNBC Monday.

"I think [Amazon] will definitely focus a lot on food [this year], as it becomes more of a staple channel," Werle continued. (See also: Will Prime Day 2017 Be as Big as Prime Day 2016?)

This year marks the third Amazon Prime Day. In 2016 sales shattered the inaugural 2015 sale, and while 2017 is expected to continue the trend, investors will be looking at performance across Amazon's growing brands, none more so than AmazonFresh.

Amazon's proposed $14 billion acquisition of Whole Foods Market Inc. (WFM) sent shudders through competing grocery chains as they face the task of competing with Amazon's geographic reach and its existing customer base. For Amazon, the acquisition will allow it to expand on its already growing AmazonFresh department. (See also: Happy Amazon Prime Day! Not For These 5 Companies.)

Along with AmazonFresh, customers are being enticed into the online grocery market through Amazon's Prime Now service. On Friday, Amazon announced it will be offering free two-hour delivery on grocery items – including alcohol – in more than 30 cities in the U.S. "As Prime members enjoy their summer adventures, family road trips and last-minute backyard BBQs, Prime Now will get them items they need in ultra-fast speeds," Stephenie Landry, worldwide vice president of Prime Now, said.

However, for those users who just want a new TV, there's no need to worry. "Amazon is planning one of its largest total volume TV deals in history with a record level of inventory but once again, the TV deals will likely sell out," Amazon said in a press release.

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