It's the right sort of drive for an NVR or a CCTV recorder, which is the job WD rates it for. It turns up when you sort everything by price per TB, which is why it's labelled here. In a NAS you'd be running it outside what WD rates it for, and for an array you want a drive that's rated for one. Five years of warranty is the other draw, and on a drive you'll leave spinning for most of a decade that's worth having.
!Watch out for
WD doesn't rate it for NAS use at all, which rules it out for an array as far as we're concerned. Being 7,200 rpm, it's in the noisier, warmer class of drive, and you'll want it somewhere you don't sit.
No Backblaze failure rate for this one. They don't run enough of them, if any, for a figure worth quoting. WD's datasheet puts it at 20 dB idle and 32 dB seeking. Power draw is 5.6 W idle and 6.9 W working on WD's figures, or 49 kWh a year if it spends the whole year idling.
Specifications
Each value links to the Western Digital page or datasheet it came from.