App marketing company Fiksu said that the cost to acquire loyal app users fell in September 2012, as the launch of Apple’s iPhone 5 triggered a 33 percent surge in downloads.

The company said that the average aggregate daily download volume of the top 200 free US iPhone apps was 4.07 million during the month, a "marginal" uptick from 4.05 million in August – although there was a "clear distinction" in activity before and after the latest Apple device hit the shelves.

"A new device launch always presents an opportunity to cost-effectively acquire and engage new loyal users – and marketers are starting to anticipate this.  As we observed, brands held off on advertising in the run-up to the iPhone 5 launch, then jumped into the fray as the phones hit stores and mailboxes", said Micah Adler, CEO of Fiksu.

The company’s Cost per Loyal User Index stood at US$1.13, down 16 percent from US$1.34 at the end of August. Fiksu said that the last time it was close to this level was May 2011, when it was US$1.10 as a result of Apple’s ban on incentive-based installs, followed by January 2012, when it fell to US$1.14 “after the holiday advertising frenzy”.