I have a video game fansite and usually relevant ads show up. One of my newsposters made a post using the word "blog" twice. Ads about blogs showed up. After seing that my CTR went way down i soon found the reason and edited the post so there was no "blog" in it anymore. 2 days later and still ads about blogs show up. How can i get rid of that? Why does it stay so long even if i removed those keywords?