• by Chuck Martin , Staff Writer, April 6, 2015

The gap between retailers that conduct a lot of mobile commerce and those who don’t is widening.

Those at the top of the mobile commerce sphere saw dramatic growth in commerce just over the last three months while the laggards stagnated, based on a new study.

The mobile share of commerce transactions of retailers at the top grew from 35% to 38% in the first quarter, according to Criteo, which measured and analyzed 1 billion transactions in 3,000 online retail and travel businesses.

Retailers in the top quartile comprise those with the highest share of mobile transactions.

Retailers in the bottom quartile showed only a 1% growth in commerce, from 6% to 7%.

The reason this matters is that mobile accounted for more than a third (34%) of all online transactions in the first quarter of this year, according to Criteo.

Those at the bottom are facing some serious trouble.

It gets worse.

While those at the top of the commerce chain see a higher conversion than average, those at the bottom see a very low conversion rates.

For example, these are the mobile commerce conversion rates of retailers with the largest share of transactions, by device:

• 2.7% -- Android smartphone
• 2.3% -- iPhone
• 2.9% -- Android Tablet
• 3.1% -- iPad

For the mobile commerce laggards, all the conversion rates are lower.

• .5% -- Android smartphone
• .9% -- iPhone
• 1.4% -- Android Tablet
• 2.7% -- iPad

As more commerce migrates to smartphones and tablets, the mobile-adept retailers continue to ride the wave.

Those not yet onboard with mobile are pretty much falling under that wave.