Blocked an IP - Still see ads

Question:
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I am having an issue. I went to "Campaigns -> Networks -> Exclusions -> Manage IP Address exclusions (advanced)", and I entered in my computer's IP Address. I used * in the fourth set of numbers in order to block out the whole area in case my computer changes IP Address. However, immediately after creating that exclusion, I google a keyword and saw my ad.

Why isn't it being blocked? Is my computer changing IP Addresses? If I did this for another IP Address , would it work? Does it take time for the change to take effect?


Answer:

I have performed an experiment myself.

• Excluded my IP as described here: http://support.google.com/adwords/bin/answer.py?hl=en&answer=61493, after I checked it with whatsmyip.org.
• One minute later, the ad was still showing
• 45 minutes later, the ad was no longer showing, on the Search Network (that's where I can test)
• In the Ad Preview, however, the ad is still showing, as it ignores IP exclusion (which means that if you want to spy on your competition, you have to use the tool, not regular searches where they may block your IP).
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