I recently launched a placement targeted campaign on Google's content network, and noticed that although my CTRs on my ads were good and I was getting a good amount of clicks, they weren't registering on my tracking software (Prosper202) and they also weren't registering with my CPA network. By the time my adwords account was showing that I had 20 clicks, my CPA network stats and Prosper202 stats only had me down for having 2 clicks, these were more than likely the inital "test clicks" that google does to make sure that your landing page is "OK". Since I was running a placement targeted campaign, I decided to find my ad on one of the URLs that I was targeting, and to click on it to see if it was working properly and taking my visitors to my offer's landing page. Guess what??? When I clicked on my ad, an error message appeared, in the location where my ad was located, saying "page not found", I knew there wasn't a problem with my destination URL because I tested it in advance. When I contacted google to inform them of this problem, they told me that this more than likely due to some websites having trouble processing the code (auto tagging) that they append to my destination URL and that I could disable this feature by doing the following (I'm pasting a copy their email response back to me): ============================================= To prevent this error from occurring, you can either turn Auto-tagging off in your account, or ask your webmaster to allow URL parameters. To turn off auto-tagging, please follow the steps below: 1. Log in to your AdWords account at https://adwords.google.com 2. Click the 'My Account' tab and select 'Account Preferences.' 3. From the Tracking section, click 'Edit.' 4. Deselect the 'Destination URL Auto-tagging' checkbox. 5. Click 'Save Changes.' ============================================== Luckily, I was able to catch this early enough in the launching of my campaign. Had I not done so, just think about how many clicks google would have continued to charge me for and not properly delivered, having me scratching my head, wondering why I'm not getting the conversions that I was expecting. Google is aware of this problem, but yet they still put "auto tagging" on by default and make no explanation of the possible issues that can occur. I wonder how many other marketers are also being charged for clicks that they aren't truly getting. The moral of the story is always use more than one tracking program when running your campaigns and keep on top of your stats. P.S. I have yet to hear back from google regarding refunding/crediting me for those bogus clicks that they charged me for.