Some of the features Google introduces do little more than collect dust, while others become extremely popular.  The Books Viewability API appears to be part of this second set, as traffic to the UK version of Google Book Search has increased by a dramatic amount since its introduction.

A year-over-year rise in visits of 73 percent would be good by most standards; books.google.co.uk accomplished that in just four weeks, according to Hitwise.  UK visits to the .com equivalent decreased during the same period, so the move wasn’t a total sweep, but it’s still noteworthy.

 Google Book Search Traffic

Robin Goad writes, “[V]isits from Google Scholar have increased, and the site has become the second largest driver of upstream traffic after Google UK.  This shift in sources of traffic may also be responsible for the changing demographic profile for the website.  Visits from users within the 55+ age bracket have increased by 53% since Oct 2007, while at the same time visits from the 35-44 age bracket have decreased by 45%.”

Finally, it seems that Amazon should be thankful for all these recent changes; a reasonable amount of traffic headed straight from Google Book Search to its UK and US sites.  And this occurred, of course, even though Google sometimes makes full texts available.

It’ll be interesting to see how far these trends extend.  Google may well tweak, or at least promote, its API in an attempt to magnify the effect.