When Microsoft gets an idea stuck in its head, it doesn't let go until it succeeds. Or, rather, it simply doesn't let go.
It's true for most of its online services that play second fiddle at best, search and maps being the premier examples. That's not to say they're worse than Google's products, they're just less used.
Bing Maps is perhaps the best example. In an effort to outdo itself, Microsoft is now
publishing a huge amount of satellite imagery, or what it calls aerial imagery since not all of it is taken from a satellite.
"Huge" probably doesn't cover it, 165 terabytes of new data is now live in Bing Maps. To give you an idea of the scale of it, Bing Maps had 129 terabytes of aerial imagery in total before the update.
The big update means one thing, much more detailed images. The entire planet was covered prior to the update, but you can zoom in much further now.