Even that can be fiddled.

USAToday used to do it via deals with hotels to put one outside your room. Boom, extra copies!

Yeah although ad buyers of any sophistication knew going in that a lot of certain newspapers were hotel copies (though arguably a lot of people read those), trade rags vs. consumer subscriptions, general vs. niche, etc. and took that into account.

They still didn't have a great idea of how effective they were a lot of the time of course.

Printing a newspaper at least costs a bit more money and there's a decent chance someone will read the copy of the paper in their hotel room. Fake Web traffic could easily dwarf real traffic.