5 Tips for Amazon Prime Day Shopping

— -- Get ready for today's digital showdown among retail's biggest giants, all competing aggressively for your dollar.

Amazon says its Prime Day -- a 24-hour shopping stunt with free shipping on more than 100,000 deals from brands of all sizes in nearly every product category it carries -- will be bigger and better than last year's inaugural event.

Even though it set sales records with 398 items ordered per second, last year's Prime Day was not without its detractors: no sizzle, all fizzle, with lackluster selection, hard-to-find deals and limited inventory, claimed those dissatisfied with the much-hyped event.

The company listened and says today's event promises a bigger selection, deeper inventory on hot items and easier-to-navigate search.

1. JOIN. To benefit from Amazon's Prime Day savings, you must be a Prime member. Sign up now for a free 30-day trial. (Set a reminder to cancel or you'll be charged the $99 annual fee at the end of the trial.)

Walmart announced that all this week, until Friday, July 15, it is offering free shipping on all online orders with no minimum purchase and no membership required.

2. GET THE APP. Download the Amazon app to take advantage of the newly-launched Prime Day-watch list. When the deals you want go live, your phone will receive an alert that it's now time to buy.

3. BUY QUICKLY. All deals are available while supplies last and those called Lightning Deals are introduced every five minutes and are limited by time. From the moment you add an item to your Amazon cart, it's held only for 15 minutes before it's moved back to available inventory for other customers to purchase.

4. CHECK COMPETITORS. In addition to "rolling back" prices on more than 100,000 items during July, Walmart.com's "Dare to Compare" feature promises the same or lower prices on identical, in-stock items. A Walmart spokesman told me, "Rather than making customers check multiple sites, we automatically do the price research for them and clearly identify our lower prices along with the price from other competitors for the same item."

To compete with the July 12 shopping frenzy, Toysrus.com and Babiesrus.com announced 15 percent sitewide-savings on most regular-priced items for the day, in addition to 50,000 toy and baby products on sale.

5. STOCK UP, REPLACE OR GIFT LATER. Since Prime Day falls outside of the traditional holiday shopping season, consider three smart strategies. Stock up on staples that you always use (think toilet paper or mac & cheese), replace every day items (think socks or kitchen storage containers) or buy now and gift later on items with exceptional savings (Amazon Echo or Amazon Fire tablets).

Another "gift later" winner: this week Walmart.com launched exclusive pre-ordering on "Pie Face Showdown," the sequel to one of 2015's biggest games, which will ship to customers more than a month before it's available elsewhere.

Finally -- a big bonus tip: Before you shop on any major retail site, register now for a free Ebates.com account. On Ebates.com search for the retailer of your choice among more than 2,000 sites, including Amazon, Walmart and other big and small e-commerce sites. Earn cash by on every purchase you make that's linked through Ebates.