Megapixels dont mean much any more. Back when cameras first came out and digital cameras were 1 megapixel and going to 2 megapixel, etc., then it was more important I believe. Today if one camera is 12 or 8 or 40 megapixel, that doesnt mean the camera is better. I actually think its worse because in some cases it makes the image HUGE yet doesnt mean its better quality. (Huge means more space, longer to send to others, etc).
Whats much more important is how well it handles light, shutter speed, close up photo ability, all those types of things. Megapixels wont tell you that. Some features like burst mode on iphone and panoramic photos on iphone are great things, and even slow motion video they have now. Those things have nothing to do with megapixel, but the average consumer is getting sold that pitch because they think megapixel is what matters.
This is from a web search below:
Megapixels measures the number of pixels written to a file, not a measure of the quality of an image. Megapixels is a nice marketing gimmick, but with regard to photography, it has no relation to picture quality (in fact, from an image quality perspective, very high megapixel counts invariably reduce image quality).