Hi there

My question is quite simple but I haven't been able to find an answer for it.

I have a website to sell books. I am trying to establish what is the
number of results that is generally regarded as "small" in a search
engine search.

For example, if a search for "google search term" turned up
100,000,000 results on Google/Yahoo!, that must be a large search.

Equally, if it turned up 520 results that's obviously a small search.

But at what point does small become large? Meaning, to clarify, what
is a search  that has turned up a large number of results rather than
a small number?

I read somewhere it was around 800,000 results. Is there any evidence
for this or any other figure please?

Best regards