As of the first quarter, more than eight in 10 U.S. mobile consumers used their devices for shopping within the past 30 days. The 84% who shop on smartphones and tablets marks a five percentage-point increase from the year-earlier period.New Nielsen data defines mobile shopping as using a device to make a purchase, research products, find stores, check prices, read or write a review, use shopping lists or comment about a purchase on a social networking site. Reflecting the broader mobile shift, more than a quarter of mobile shoppers say the now buy more frequently via mobile than on their PCs. Mobile shoppers are split evenly by gender, though women are more likely to purchase physical goods than men. They also skew younger and more affluent than the general population. Most (57%) are under 45 years old and 34% are under 34, up from 29% from a year ago. The share of mobile shoppers in the 25-34 age segment has increased the most in the last year, to 28% from 24%. In terms of income, Nielsen’s first-quarter “Mobile Shopping Report” noted wealthier consumers tend to be more active shoppers on devices, with 35% earning more than $100,000. The study also pointed out that the share with household incomes below $50,000 has grown the most, up eight percentage points to 21% from a year ago. Overall, mobile shoppers with lower and middle incomes made up more than half of the total. The expansion of mobile shopping across income groups likely reflects the greater availability of lower cost smartphones and tablets in the last year and wider device adoption overall. Findings from the Pew Research Center last month last month estimated the majority (56%) of American adults own a smartphone and a third (34%) have a tablet. In the latter case, tablet penetration has jumped from just 3% in May 2010, while smartphone adoption is up from 35% two years ago. Research also indicates people favor tablets over phones when it comes to m-commerce. Nearly a third (30%) of U.S. tablet owners have made a purchase on their devices, compared to only 13% of mobile phone users, according to a Forrester study released in May. M-commerce sales overall increased 31% in the first quarter, accounting for 17.4% of total online sales, up from 13.3% a year ago, per IBM’s Online Retail Index study.