I use "cid=ppc" query parameter on my Campaign Landing page urls for Google and Bing. So that by using following channel processing rule, it will be tracked under paid search. But some of the visits for this query parameter urls received from Direct channel. Also for Google Shopping, I use "cid=google_shopping" (but not used in channel processing rule) and those visits also not tracked under paid search whereas tracking under Direct channel. When I compare the Google & Bing data with Omniture it varies.
My Paid Search Detection rule contains following Filters: "ppc", "&ppc=", "?ppc=", "?pid=", &pid="
Also I can see cid=ppc contain pages aas entry pages for natural and direct channels. How does it possible? If anyone has idea on fixing this tracking, please let me know?
as far as I can see it might not be a problem of the processing rule, rather a reporting issue.
what you are looking at are the "entry pages" by "marketing channel". be aware that the "entry page" is not only the first page of a visit, it consists throughout the while visit (that means, it is available at all hits of a visit container).
Now just assume the following: a user comes to your site with paid indication (matching above "entry page" and marketig channel rules). the visit would then be considered in your reporting as expected (desired entry page and marketing channel).
but if the same user comes back to your page by another channel and within the technical visit window (eg. within 30 minutes after last hit), it would count to the same visit and keep the entry page while counting to another marketing channel! thus the visit would appear on 2 breakdown items (paid channel and other channel) but only once for the total of the entry page (btw: that is the reason why your single items don't match the total).
if you only want to see the pages where a user arrived matching the desired marketing channel you should use another report: take "page" as dimension and "marketing channel instances" as metric (or "last touch channel" / "click throughs", depending on interface). maybe you even add a segment where youbset the filter to only show the marketing channel hits of "paid traffic" to further narrow the results...