The market for fingerprint readers (from capacitive to thermal, and consumer- to government-grade) is estimated to be worth about US$3.5 billion at present. This worth is thought to grow to as much as $7.1 billion by 2024, however. The scanner type we have become most familiar with is thought to represent the largest sector over these next 5 years.
https://www.notebookcheck.net/The-fingerprint-scanner-market-s-value-is-set-to-double-over-the-next-5-years.435626.0.html