Apple Inc. can't exactly force its older iPhone users to upgrade to the iPhone 6S. But that doesn’t mean it can’t regularly nudge and remind them that there’s a new shiny smartphone available every chance they get — even when they’re just visiting the App Store on their device.

Several iPhone users this week spotted iPhone 6S pop-up advertising that began appearing when they browsed the App Store through an iPhone 5S or earlier device. The ads, which tout Apple’s smartphone as “ridiculously powerful,” nudge users to learn more about the device and give them an opportunity to upgrade right on the spot. It appears that Apple has started the ad campaign across older devices in several countries, with several Twitter users posting the screenshots of the ad in different languages on Twitter.

It’s not uncommon for Apple to cross promote its products through banners and other images on its digital properties. But this time around, customers have to hit the skip button to get back to their activities — much like the advertisements seen on some online publications or in third-party apps.

One reason for Apple to do this is the all-important holiday quarter where investors are looking to see if the iPhone juggernaut can out-do last year’s record-breaking quarter of 74.5 million iPhones sold. This time around, Wall Street consensus estimates project iPhone sales will reach 78 million in the December quarter. That’s despite a global smartphone market that is expected to slow its growth in shipments to 9.8 percent by the end of the year, down from 27.6 percent in 2014, according to IDC.