Apple and incentivised download outfit Tapjoy have a long and turbulent relationship.

It was back in April 2011, when Apple first tried to ban iOS apps and games using Tapjoy's offerwall to generate revenue and installs.

In return, Tapjoy attempted to get around the restrictions by going cross-platform, adding strong Android support, and rolling out a web-based solution that Apple couldn't control within its App Store rules.

Now, according to a financial report from Glu Mobile, one of Tapjoy's key partners, Apple has had another swipe at the system it hates so much.

Smackdown

"Two days after our October 9th preannouncement press release Apple informed us of its prohibition of incentivised advertising to include any linkage to external HTML5 sites, which is affecting our revenues from the direct channel," pointed out Glu's CFO in an earnings call.

"This has resulted in an approximate 6.5 percent reduction of our prior fourth quarter guidance or a $1.75 million reduction in fourth quarter guidance."

Of course, for companies like Glu who are committed to the free-to-play business model, the money they generate from services like Tapjoy is vital.

With iOS continuing to be the mobile strongest gaming platform, despite the rise of Android, anything Apple does to disrupt how such services operate will have a significant impact on almost all free-to-play companies.

As for Tapjoy, its CEO has fought back, saying the company provides a much-loved service.