It's one of the most important rules in any business that manufactures goods for sale. It's pretty pointless designing a product that doesn't have a market. Any businesss has to know its market, regardless of what they are trying to provide, which is why the major companies (including Canon and Nikon) spend so much on market research. How many people complained about the main problems in the 5D MkII being the poor AF and relatively low frame rate, the general issue of Canon cameras having higher noise at high ISO than Nikon over the past 3-4 years? It isn't an accident that Canon has addressed those issues and not increased resolution. Noone was complaining about resolution and dynamic range until the 5D MkII and D800 were released, so equally, Canon didn't address those points. Conversely, the main area where the D700 was considered inferior by some was resolution, which Nikon addressed (with Sony's help), whether they went furhter than necessary or not is down to personal opinion and needs. In many ways, the D700 was the better allrounder relative to the 5D MkII and the 5D MkII was the better studio/landscape camera, now the situation has arguably reversed with the MkIII and D800. However, I'm still to be convinced that Nikon has a significant number of lenses that can cope with that extra resolution, which could be why Canon has been slower to come out with a high resolution sensor; they certainly seem to be announcing/releasing a lot more lenses recently than they have in the past few years.