This seems to depend on a lot. I rarely see "No results found". That is a completely valid result in my opinion. I often see pages that doesn't contain my se

This seems to depend on a lot. I rarely see "No results found". That is a completely valid result in my opinion. I often see pages that doesn't contain my search string. Sometimes is is something trivial like query: "something about x y and z" result contains: "... something about x. Y and Z however..." which is understandable. Often though I have no clue how a result got there. Maybe it is linked to using a certain text (link bombing)? I don't know.