(NBC News) Amazon Prime Day has become summer's Black Friday.
The 36-hour sale officially starts today at 3 p.m., offering deals on thousands of products.
RetailMeNot.com's Sara Skirboll says Amazon's marketing marvel has forced other retailers to stage big sales today as well.
"Think Walmart, Macy's, think Kohl's, places like that. Even the GAP and JCREW," Skirboll notes.
Although Amazon's Prime Day is meant for Prime members who pay $119 a year for free shipping and access to the streaming TV service, there's a month-long free trial period.
You can sign up for the free trial this morning and start using it this afternoon, just as Prime Day begins.