Smartphone prices had long flirted with the $1,000 threshold, but in 2017, Apple did away with the formality and eclipsed the unspoken barrier, marking a new era for smartphones. Samsung is not far behind, and many others will likely follow in the ensuing years. This has led to an unexpected consequences for big smartphone makers.

According to The Wall Street Journal, new data reveals refurbished models now account for 10-percent of smartphones sold worldwide. That means it is the fastest growing smartphone segment right now. This isn’t necessarily the segment manufacturers want to see grow, yet it’s happening regardless.

Refurbished devices have long been popular in developing countries, but now the trend hast caught in the U.S. and Europe. Apple has greatly benefitted from refurbished models, offering discounted models of older iPhones with the full benefit of its AppleCare program. These devices cost hundreds of dollars less than the iPhone X.

The iPhone X was not a flop by any means. However, sales numbers proved to be softer than expected.

Another side effect is the increment at which customers upgrade smartphones. According the the report, back in 2013, upgrade cycles were under two years (23 months). Now, the cycle has increased to 31 months and is expected to reach 33 months next year. People are holding onto their devices for nearly two and half years at minimum.

Apple broke the $1,000 barrier on purpose knowing this and its foresight paid off in 2017. iPhone sales declined, but with the drastic price increase, it still saw record-breaking revenue numbers.

But as refurbished models gain in popularity and customers hold onto their devices for longer, sky high revenue for companies like Apple and Samsung may soon take a big hit. It may just be a matter of time.