I have a connection which gives me a dynamic ip and have noticed that at times it seems Google has my location set automatically and have done searches without a locale keyword (like "roofer") and gotten local search results. I will at times get an ip that must be routed through other locations because I get irrelevant local results.
A minute ago I did the same thing and did not get any local results. I noticed that on Google there was a spot to enter my zip - searches done after that deliver a local result without needing any city name.
Does anybody know the answer to this? Does Google know where a visitor is coming from?