Figures from ABI Research show that 17% of US smartphone users who installed software on their devices spent at least $100 (around £69) in 2008. The company also points out the price difference when buying software for different devices; downloads from Apple's iPhone App Store often sell for $1 or $2, while software for other devices can cost several times more. It says this difference can force developers to choose between selling high volumes for the iPhone or making more profit but selling less software for other devices. [Press release]