An online poll of U.S. iPhone owners found that only 9.3% were planning to upgrade to the iPhone 7 due to the expected design being so similar to the iPhone 6/6s. That contrasts with 25.2% who would upgrade for a brand new design.

At this point, it’s unclear whether Apple is simply holding back significant design changes for a special 10th anniversary iPhone, or is – as a Nikkei report suggested – switching to a three-year major refresh cycle. But the Quartz survey indicates that the latter would be a dangerous move …

Some 34% of respondents said that if Apple switched to a three-year cycle, they would adjust their own upgrade pattern to match – upgrading their phones every three years rather than two. Add in those who said that they were ‘somewhat likely’ to do the same, and the total number hits 70%.

The risk has been increased by carriers switching from all-in plans – where customers paid a single monthly fee which included the bulk of the cost of the phone – to ones where the two elements are separated, so people can save money by upgrading less frequently.

The survey was based on 525 U.S. iPhone owners whose demographics are representative of the population.

If you need to bring yourself up to speed with what we’re currently expecting from this year’s iPhone, check out our iPhone 7 guide.