Mobile marketing company Fiksu Inc has released a new report with its Cost per Loyal User index (CPLU), which “measures the cost of acquiring a loyal user for brands who actively market their apps,” and it found that the costs associated with acquiring mobile users is now $3.09. While that figure is only 10 percent higher than the previous month, it represents a surprising 113 percent increase year-over-year.

“This relentless growth is representative of a larger trend, reflecting the expanding power of mobile marketing to reach app users and the rising costs happening in parallel,” Fiksu noted in its report. “Entering another record-breaking month, marketers and brands must face the inevitable rising tide: mobile marketing is maturing and becoming more expensive. ”

As the mobile app market matures, the industry is becoming increasingly more saturated, and the competition has become fierce in markets around the world. Earlier this year, the head of iDreamSky Technology, Jeff Lyndon, said that the early “land grab” in the Chinese mobile game market was drying up, and funding would become harder and harder to get.

“This year for the Chinese market, a lot of us are predicting a cold winter,” Lyndon told GamesBeat at the time.

According to Fiksu’s Cost Per Install index, which compares the cost of installs directly driven by advertising, one app install on iOS costs $1.53 in advertising, a 46 percent increase from the previous year. The cost on Android is $1.74 per install, which is a 63 percent year-over-year increase.

“In the coming months, a top priority for marketers should be continual adjustment and employment of programmatic media buying methods to spend marketing budgets as wisely as possible,” Fiksu said. “April generally means less competition and caution with budgets. That said, this historic trend may fluctuate in April as the Apple Watch has made its highly anticipated debut and the flurry of activity and excitement may drive additional activity for iOS marketers. In either scenario, keeping existing app users engaged today should be a top priority for any brand looking to engage with users on the Apple Watch tomorrow.”

In a statement, Fiksu CEO Micah Adler added, “Sustainable success will be found by brands that use more precise forms of targeting to reach the right mobile users: those who will engage with an app and become loyal over the long term.”