Amazon isn't the only retailer celebrating Amazon Prime Day

Call it a glorified ad campaign. Call it whatever you want, but Amazon's third annual Prime Day is here. Amazon introduced its first Prime Day in 2015 as a super sale exclusive to Prime members. Last year's installment increased global sales more than 60% compared with the first year. Unlike past iterations, which ran 24 hours, this year promises an extra six hours of savings, stretching from 6 p.m. Pacific Time Monday until the end of the day Tuesday.