For the second straight year, Houston was ranked as the nation’s most “mobile shopping savvy” city, according to a study by the Interactive Advertising Bureau.

Runner-up was Seattle-Tacoma, moving up from No. 10 in 2011, with San Francisco, Los Angeles and New York rounding out the top five. Breaking into the top 10 this year was Boston at No. 9.

The results are drawn from a biannual survey of over 20,000 consumers conducted in June about their media behaviors and influences. The trade group’s Mobile Center of Excellence based the rankings on four criteria: ownership of a mobile device (primarily smartphones or tablets), propensity to be influenced by mobile coupons, owning a mobile retail app, and owning a social media app.

For each data point, the IAB created an index for each DMA relative to the U.S. national average. It then combined them into a single metric, weighting device ownership most heavily.

“Determining which cities are more receptive to mobile can be a critical component in driving successful campaigns that reach audiences in the palms of their hands,” said Pam Goodfellow, consumer insights director, Prosper Mobile Insights, which partnered with the IAB on the study.

-More than 80% of smartphone owners have accessed retailer sites or apps on their device

-68% of Americans owned a smart mobile device (smartphone, tablet, or eReader) in 2012, up from 57% in 2011

-Nearly half of U.S. consumers say they have a QR code (barcode) reader app on their mobile device

-Smartphone shoppers are evenly split by gender and tend to be younger than desktop-based retail shoppers

-Over half of smartphone owners, and nearly 30 percent of tablet owners, have used their devices in a store in the past three months