I don't know why this is happening. I have a very broad keyword, for example, Computer Repair I went into google adwords ad preview/diagnosis, and typed it in from a specific city, say new york city, and I rank in the top 10. However, I then changed the city to a different one in new york, and I don't even rank in the top 100. Why is this? My keyword doesn't have a city in it or anything, it's just a broad keyword like Computer Repair