Google 's ads are everywhere , but new data  from Marin Software suggests that one particular sector may be earning surprisingly huge revenues for the search company: Tablet displayed ads may bring in $5 billion in 2013. Ad effectiveness also jumped by 31% in 2012, and the conversion rate for search ads on tablets was approaching the figure for desktop ads at the end of year.
Google's recently bumped the price of display ads for mobile devices, and incorporated them into online ad packages it offers even if ad partners only requested desktop ads. It's an open confirmation that we're entering the post-PC era . And lest you doubt it, Marin is in the business of web-search ads, so it seems well placed to know data like this. Apple, of course, leads the tablet race, and is separately rumored  to be earning $1 billion from Google for search on mobile devices.
[Image: Flickr user C. Regina ]