Amazon's fourth annual Prime Day kicked off Monday to much fanfare, but it didn't quite go off without a hitch. Some users [reported](https://twitter.com/CNET/status/1018934859505385472) getting error messages, while others got stuck in a loop that kept redirecting them back to the main sale site. The issues came in the opening minutes of what the e-commerce giant has touted as a shopping holiday bigger than Black Friday or Cyber Monday. Research firm eMarketer estimated the company could bring in revenues of as much as $3.4 billion during the event, eclipsing the estimated $2.4 billion spent last year. Whether the glitches affect results will be closely watched by analysts and investors ー shares of Amazon, which hit all-time highs early in the day Monday, pared gains after news of the problems. Prime Day began at 3 pm ET on Monday and lasts 36 hours. This year's event is six hours longer than last year's.
