I have subdomain: blogs.mydomain.com (it runs 2 banner ads and 1 Text link) - Added a URL channel for it.
Now the ONLY above 3 ads: added to a custom channel same name as URL channel. The custom channel named the same blogs.mydomain.com.
Now the difference for last 24 hours for the both channels with same name, showing on one subdomain and same ads. example below.
blogs.mydomain.com (URL Channel) -> 50,000 Impression -> 3.25 CTR -> $20 earnings
blogs.mydomain.com (Custom channel) -> 25,000 Impression > 2.50 CTR -> $10 earnings.
Why in the Gods name this difference arises when both are counting the same ads one by using custom channels and other by URL channel. Simply I have added the ads displayed on a subdomain to a custom channel and it's showing almost 50% differece.