October turned out to be a tremendous month for Apple and app developers, according to Fiksu. The new iPhone 6 and iPhone 6 Plus had stellar sales that drove high levels of app downloads.

As reported by GamesIndustry International, the launch of both of the devices managed to push App Store downloads to record heights for the month of October, with 7.8 million downloads calculated across the top 200 apps per day. That shows a wild 42 percent increase from the 5.5 million downloads from the previous month.

As a result, however, the general cost per install for iOS managed to increase as well, showing a jump of 21 percent to $1.46. That’s on a month-by-month basis, while year-by-year shows an even larger increase by 59 percent. By comparison, as earlier stats showed, Android showed a CPI of just $1.01, up a meager 1 percent from the prior month, and 2 percent from the previous year.

“An important lesson this month for marketers is the value of nurturing user loyalty prior to device launches and gift-giving seasons,” the report states. “Despite the marked rise in advertising costs particularly on iOS, the Cost Per Loyal User Index (CPLU) indicated a slight decline in October to $2.16 from September’s $2.25. This decrease is a result of the tendency of app users to quickly re-download their most-used ‘vital’ apps during upgrades. The first set of apps users download on their new iPhone 6’s are likely to be those they can’t live without, which makes them much more likely to become loyal users of those apps.

“In the coming months, marketers should also look to capitalize on untapped Android opportunities. While the Cost per Launch (CPL) Index, which tracks the costs of driving engagement from mobile users, showed increases across the board on iOS, October saw a 26 percent year-over-year drop in Android CPL. Combined with the slighter increases on Android’s October CPI numbers, this may be a good place for marketers to spend advertising dollars as iOS costs only continue to rise.”

The charts below from VentureBeat also show the fluctuations between Cost Per Loyal User Index, as well as Cost Per Launch Index — and, as you can see, Apple’s increased numbers over Android have just gotten bigger over the past few months. In fact, the last time the two were even was back in January, with a  cost of $.16 per launch.

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