> From usability perspective, progressive is usually good, because the user gets feedback that something is going on. Also if you’re on a slow connection, progressive JPEG is preferable because you don’t need to wait for the whole image to arrive in order to get an idea if it is what you wanted. If not, you can click away from the page or hit the back button, without waiting for the (potentially large) high quality image.

_Bottomline_: Progressive JPEG is the ticket to [flawlessly serve retina-quality photos for the new iPad](http://duncandavidson.com/blog/2012/03/photography_on_retina) today.