How important are megapixels?

Hasselblad's announcement of a medium format camera that could capture 400-megapixel images got us thinking: are the 'megapixel wars' of a decade ago really over? And how many photographers would actually need such high resolution? (Very few, we suspect.)

Recently, most camera manufacturers have promoted features other than resolution when advertising cameras, although most consumers still check the megapixel count of cameras before they buy. So why do we obsess about megapixel counts and ignore other, often more important, features? And with more pictures being taken with smartphones and shared via social media, how much do megapixels matter?

Megapixels resonate because numbers are easy to understand and quantitative measures are difficult to dispute. High megapixel counts imply superiority because we're conditioned to believe that more of something is always