Advantages of Google AdSense URL and custom channels

One disadvantage of adding Google AdSense directly from Blogger LAYOUT is that you cannot use custom channel to track the performance of your ad units. Fortunately, there is also URL channels which tracks the total earnings from a particular blog (URL). Now if you track the custom channels forAdSense units generated directly from Google AdSense, then by simple subtraction of the total earnings from custom channels from the total earnings for the blog (URL) you can get what is left, that is earnings from the AdSense units inserted directly from the Blogger LAYOUT placed after each each post. This was how I was able to get a Google AdSense channels report for this blog which is my main blog for bloggers.