One-third of respondents to a survey commissioned by PopCap Games said they had played a game on their mobile phone during the last month, with one quarter stating that they had played in the last week. Of the 2,425 participants polled across the UK and the US, 43 percent of those who had played in the last month had upgraded a free trial game to a full, paid version in the last year, with 23 percent of device usage time (excluding calls) spent playing games. The research was conducted by Information Solutions Group, using online surveys.