(NYSE:

) is pulling out all the stops to get customers to shop in its stores and on its website. The retailer launched a four-day

sale on Monday, encouraging shoppers to drop by everyday for the latest deals. Starting tomorrow (Friday, December 20), Best Buy stores will extend their hours and remain open from 7:00 a.m. until midnight. The extended hours will remain in place through Monday, December 23. The Samsung Galaxy S4 is among Best Buy's

, with the new phone currently retailing for $49.99 ($150 to $200 off the MSRP). The deal includes the Best Buy exclusive color -- Blue Arctic.

Shoppers have until 12:00 a.m. EST on Friday, December 20 to cash in on the latest

, which just happens to be an HP Pavilion TouchSmart 20" Touch-Screen All-In-One Computer. Regularly selling for $599, Best Buy is currently offering the computer for $399. Best Buy has also

each 13-inch MacBook Air. This deal is not quite as good as the retailer's Black Friday sale. At that time, Best Buy took $200 off the 13-inch MacBook Pro with Retina Display. But it's still a very good discount for anyone who is shopping for a MacBook Air. SanDisk's 16GB memory sticks typically sell for $27.99, but Best Buy is

for $8.99. There haven't been many discounts for the Kindle Fire HDX, but Best Buy is currently selling the tablet for

. Amazon isn't the only retailer that took $5 off Chromecast -- Best Buy

. PlayStation Vita is

. Shop now and get $25 off the $200 device. Need a new iMac? Each model is

at Best Buy, with discounts coming in at $160. Even the first-generation 64GB Surface RT is on sale. But the discount only amounts to

the standard price of $379.99. All of these sales appear to be available both online

in Best Buy stores across the country.

If a price differs in store from the one shown online, ask for a price match. Best Buy happily matches the price of

retailers, so there's no reason why it wouldn't match its own online price. Disclosure: