Amazon's turning 20 on July 15th and will celebrate the occasion by giving you another reason to sign up for Prime. The company is launching Prime Day, a "global shopping event" that promises to have "more deals than Black Friday." Unfortunately, you'll only be allowed to participate if you give Jeff Bezos $99 a year, or you take this chance to sign up for the free trial. The event kicks off at midnight PST on July 15th, and is open to all members in nine countries including the US, Canada and the UK. Of course, since Amazon sells more than just big-box electronics, you'll also find lightning deals in every department from clothing and sports through to patio furniture. We don't know if this is intended to become an annual event, but we've asked the company, since it'll take a few years for the diary makers to catch on.