I'm just having a play around with Google web api and noticed some strange results especially with estimatedTotalResultsCount. Has anybody noticed any behaviour like this? I checked it against what turned up in the normal google web results and they were completely different. So I tried again with the api and it gave me a completely different result. my results for the same keyword: api 1st go: 1,800,000 web 1st go: 2,800,000 api 2nd go: 370,000 web 2nd+ gos: 2,800,800
The API gives totally inconsistant results from one query to another as it seems to randonly select a datacenter. If you do a query directly after another one then you can often get 2 totally different results. Just another way for google to keep us guessing really.
A specific DC can have big variatons in est. result too over time. And G.com has that too, it is not only the API. I think it is a very "estimated" number to save database calculations.