For quite a while there’s been a puzzling gap between the advertising value of a user on the web, on a smartphone and on a tablet.

This value disjunction seems counter-intuitive.  Adoption and usage of mobile devices has exploded and personalization allows for shrewd targeting of messages to place and time.

Some recent data shows us that the gap between the three formats is narrowing.  Mobile devices are increasing as a percentage of overall click-thru and the value of those clicks is increasing.

According to a recent analysis by The Search Agency, tablets have increased to a 9.8% share of the click-thrus on paid search ads in the fourth quarter of 2012, up from 4.2% the year prior. The combined share for smartphones and tablets increased to 22.4%, up from 12.4% the year before.

As clicks have grow, so has the value of the audience.  Marin Software recently shared research that shows the conversion rate of paid search ads on tablets is 85% of the rate on computers.  Search ads on smartphones convert at 72% of comparable ads on computers.

Ad clicks via tablet devices are projected to account for 20% of Google’s paid-search revenues in the US by December 2013, up from 10.7% a year earlier. according to the report.

The Search Agency data suggests that marketers are still enjoying a discount in the cost per click on mobile devices that is disproportionate to the relative conversion rates of the devices: tablet cost per click was 78% of computer cost per click in the fourth quarter, while smartphones less than 50%.

Personal mobile devices — smartphones and tablets — are going to provide a second life for companies that provide compelling content to consumers. The form factor is a skeuomorphic replacement for the magazine; that shift provides a combination of consumer engagement and advertising scarcity that will help to drive up rates to levels that can support content.

According to eMarketer, the US mobile search market will top $3.54 billion in 2013, up more than 80% from 2012. That’s a sign of what is to come.