Good trick, Danny.
Same search in Yahoo returns nothing, but a search for the letter "a" returns
Results 1 - 10 of about 11,500,000,000
while in Google a search for "a" gives
According to the above numbers and reasoning:
1. could we say that in Google 1.6 billion pages do not contain the letter "a"?
2. could we say that Yahoo has an index of at least 11.5 B pages
Both search engine results either can be trusted or can be rendered as suspicious, depends on who you ask.
Trying to estimate the size of a search engine from scores driven by queries is not a reliable approach and raises more questions than answers.