Daniel Acker | Bloomberg | Getty Images. Amazon's blockbuster Prime Day promotion is not an indication that the company feels threatened by Wal-Mart or Alibaba, analysts said.

Doorbuster? Or tag sale?

That’s the question many Amazon (AMZN) customers seem to be asking as they browse the retail site during a shopping extravaganza Amazon has hyped as bigger than Black Friday. Prime Day, as Amazon calls it, is supposed to be a mid-summer opportunity to get killer prices on some of the year’s hottest products. But many shoppers are logging on to find underwhelming deals on oddball offerings such as beer coolies, nose vents, shoehorns and cat-training aids.

Given Amazon’s heft, some retail analysts have speculated that the online dealfest could reshape the whole retail landscape. Instead, Prime Day seems to be shaping up as a flop, as social media posts such as those posted below suggest.

This @amazon sale is a joke. A sale on Thomas the Train and Rock em' Sockem Robots! Woohoo! #amazonprime thanks, but no thanks. — Dan Dawley (@swelltv) July 15, 2015

#AmazonPrimeDay is like shopping a garage sale - you go in with high expectations and walk away with more junk. — Amy Kreis (@amykreis) July 15, 2015

Super disappointed in @amazon #PrimeDay. Is it possible that @Walmart is having better sales on their website than Amazon? I think so. — Joey Santos (@joeythedesigner) July 15, 2015

Since Walmart (WMT), Amazon’s biggest competitor, vowed to match Amazon’s deals with “rollback” specials of its own, Yahoo Finance decided to quickly rank each retailer in 4 categories, to determine which wins the first annual Prime Day slugfest. In our estimation, Walmart walloped Amazon, by a score of 14 to 8 (with 20 being the highest possible score). Here's our grading system:

View photos Sources: Amazon.com, Walmart.com, Yahoo Finance More

Amazon characterized Prime Day as a success, boasting in a press release that order rates halfway through the day exceeded those during Black Friday, the day after Thanksgiving, in 2014. Among the day's sales leaders, according to Amazon: a Kate Spade purse that sold out in less than a minute, a set of Rubbermaid storage containers for $14.99 (28,000 sold), and a 50-inch Samsung 3-D TV for $999 (1,200 sold).

Still, the come-and-go deals required shoppers to monitor the site for hours or join a waiting list for "upcoming" offers, which seemed to frustrate many users. Here's our review of Prime Day during the first half of the day, in the four categories we graded:

Relevance. Walmart offered a lot of mainstream products typical families can use, while Amazon offered a strange collection of miscellania that could have come from some gigantic leftover bin. Among Walmart’s top rollback specials, for instance, were paper towels, toilet paper, diapers, mattresses, sheets, a stroller, a crib, TVs, smartphones, printers and a lot of women’s clothing. You know, stuff people use every day.

Amazon listed everyday items too, but it took longer to find them. When we spot-checked its top listings, for example, we found useful gadgets such as a router and digital camera, plus lots of smartphone cases and charging cables. But the same check also offered a baffling array of bottom-shelf items, such as a thermal laminator, a turmeric curcumin dietary supplement, anti-callus gloves, a rifle scope and many other specialty products. Amazon offered thousands of “lightning” deals that came and went during the day, so shoppers logging on at different times would see different offerings. In general, however, offbeat items seemed to outnumber everyday products. (But "Fifty Shades of Grey" fans are in luck: the unrated Blu-ray and DVD could be yours for $13.99.)

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