Every report I’ve seen comparing conversions on PCs, smartphones and tablets shows tablets as having much higher conversion rates than smartphones. Part of the reason is that people rarely complete transactions on their smartphones — they tend to buy later on PCs or tablets or offline.
That’s why it’s both interesting and curious that comScore has data showing the percentage of e-commerce transactions happening on smartphones being almost 2X of tablets. However, as a percentage of the total value of e-commerce in the US mobile (smartphones + tablets) still constitutes less than 10 percent.
The total value of US mobile commerce for the first half of 2013 is $10.6 billion estimates comScore. Of that 6 percent is coming from smartphones and 3.5 percent from tablets.
Events is a particularly fruitful area for mobile commerce apparently, coming it at nearly 16 percent of sales for the category.
The explanation for the comScore numbers may simply be that there are many more smartphones than tablets in use, although the latter numbers are growing rapidly. Perhaps as many as 150 million in the US have smartphones while there are roughly 85 million tablets (extrapolating from Pew Research survey data).
There are thus twice as many smartphones (roughly) than tablets, which could explain the data in the table above.