One of the changes we’ve made to the MapCast service was to equalize the usage cost per image regardless of what image format was selected when using the WMS service. As you may know our WMS service can serve images in JPEG or PNG format depending on your settings in your GIS or CAD application, these image formats both have their advantages and disadvantages; JPEG images are highly compressed resulting in smaller file sizes but lower quality images while PNG images have less compression with higher quality images that support transparencies but larger file sizes.
With our new MapCast service we automatically adjust the usage to reduce the cost of PNG images to be in line with JPEG image. For some customers this may result in a significant savings allowing you to download more image from the service for the same bandwidth.