They app, they shop. A new report from Knowledge Networks has found that among those who use apps on their smartphone, 40% will refer to them at least "sometimes" when making decisions while shopping. Of the more than 1,000 consumers surveyed 32% already say they are more inclined to buy from companies that advertise in apps - a much higher proportion than for other emerging platforms.

The report, “Smartphone Apps: General and TV-Related Usage,” also found that iPhone owners typically have 29 apps on their phones - compared to 19 for Android users and four for BlackBerry users. iPhone owners are also about three times more likely to have paid apps compared with non-iPhone users, and are much more likely to be receptive to advertising in apps.

"The portability of apps means that they can travel with people as they shop, and the proportion of smartphone users – particularly iPhone users – already using them while shopping is eye-opening," said David Tice, Vice President and Group Account Director at Knowledge Networks. "We also found that, even before iAd has launched, advertising in an app is an effective way to take advantage of this symbiosis. Taking the opportunity further by creating a custom app is another, potentially more powerful approach."

The report also shows that among app owners ages 13 to 54:

• 40% say the ads in apps are "usually relevant to my needs and interests."
• 46% report that the ads generally fit well with the ad context.
• 70% say ads are a fair price to pay for getting a free app – even though an equal proportion feel that ads interfere with their enjoyment of apps.