If you use more than one custom channel at a time, the total custom channel amounts will be higher than your url channel.
OR
If people can reach your page through other urls, your custom channels will be higher.

Example:
You have a url channel on www.example.com/SnazzyPage.html

You have custom channel SnazPage1 in the ad.

Someone visits
example.com/SnazzyPage.html
or
123.45.67.89/SnazzyPage.html
or
ww2.example.com/SnazzyPage.html
or
123.45.67.255/GoogleCache?cache=SnazzyPage.html

and he or she clicks an ad, your custom channel SnazPage1 will register the impression and click, but your url channel will not.

Check your logs! :)

Good Luck

[edited by: RonS at 6:01 am (utc) on Mar. 18, 2007]

1) I use only one custom channel for each unit.

2) i have added example.com as my url channel and not www.example.com I thought example.com is supposed to capture all the data.

I don't think to, but there's a simple way to check that: Add the other one too! :D