Considering that Amazon owns Woot.com, the go-to place for single-day sales, it's amazing how often incredibly steep deals can be found on the Gold Box portal. Today it's another round of dramatic discounts on SanDisk's line of flash storage cards and drives. For Android users, the MicroSD cards are the most interesting: you can grab a Sandisk Ultra 32GB card for $19.99 (71% off the regular price of $69.99) or the 64GB version for $41.99 (58% off the regular price of $99.99).

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These would be good deals even on standard MicroSDHC/SDXC cards in these capacities, but remember that the "Ultra" series is made for intensive read and write speeds. Both are given Class 10 speed ratings, which means a minimum write speed of 10MB per second (though SanDisk claims up to 30MBps). They're usually intended for HD video recording or ultra-fast still photo shooting, but it also makes them great for storing apps on the external card, assuming your hardware (or rooted software) supports it.

As always with Gold Box deals, Amazon Prime members can get free two-day shipping and reduced shipping costs on even faster options. The 16GB version of the SanDisk Ultra card isn't on the Gold Box page, but it's also on sale: $13.59, 32% off the $20 retail price. There are good deals on Extreme SDHC/SDXC cards and various high-capacity flash drives as well, if they strike your fancy.

Amazon's Gold Box deals are good for one day only, and the low prices mean that the stock of sale items often runs out quickly. 

SanDisk Ultra 32GB MicroSDHC card for $19.99 (71% off)

SanDisk Ultra 64GB MicroSDXC card for $41.99 (58% off)

Source: Amazon Gold Box