Warm up those fingers. Amazon Prime Days are almost here. Amazon’s huge summer Black-Friday-like sales event is June 21st and 22nd, and if it’s anything like last year, Amazon shoppers will spend millions of dollars.

Electronics, especially those Amazon products, will be deeply discounted. Third-party sellers also drop prices and offer those ‘lightning’ specials throughout the days.

Sure, you can find some great bargains, but don’t ignore the competition. Walmart, Target, and Best Buy are holding their own summer sales to coincide with Prime Days. Shoppers who are poised to tackle Amazon's Prime Day sales would do themselves a favor by checking out Amazon's competitors.

Best Buy, for example, calls their 2-day sale "The Bigger Deals." Look for low prices on TVs, game systems, laptops, home entertainment, appliances, and other electronics.

A few pre-sale postings find some Amazon and Apple products on sale and TVs and computers a few hundred dollars off their regular prices.

Walmart's "Deals for Days" starts a day ahead of Prime Days and goes through the 23rd. Walmart has a little bit of everything on sale including toys, electronics, clothing, and home furnishings. A sneak peek shows robot vacuum cleaners at half-price and TVs and computers $30-$40 off.

Target calls its event “Deal Days” which starts June 20th and ends the 22nd. Not much on its website yet, but I have found Target's early Deal Days leaked ads show 20-30% off on electronics.

For the past few years, eBay has held a Prime Day type sale but so far, there's no announcement on its website.

Things do sell out during Amazon's Prime Days. If you have trouble catching the deals, Target, Walmart and Best Buy will match Amazon's prices with some restrictions. Before ordering, go online and chat with their customer service specialists to get the best price. The best way to find the best Prime Day deals is to download the apps of stores you want to shop.