Amazon 'Prime Day' sales gimmick is back this July

The e-commerce powerhouse launched the discounting event last year to commemorate its 20th anniversary and to advertise its $99 annual Prime loyalty program, which offers free two-day shipping, during sleepy summer shopping months.

[...] Wal-Mart is also advertising online shopping discounts in July as well as a 30-day free trial of a two-day unlimited shipping service.

Amazon said it was a success, with 18 percent more orders placed that day than the prior year's Black Friday, the shopping day after Thanksgiving that's typically the busiest day in retail.

To attract subscribers, the company has added grocery delivery, one-hour delivery in some cities, more video streaming and a smart speaker called the Echo that syncs with Prime music.