Here is the list of organizations that currently use the VP9 via wikipedia. Its your opinion whether or not that's not enough in circulation for you:
Bavarian State Police — Around 40,000 units ordered. Police officers will be equipped with the SFP9 by 2019.
Berlin Police — 24,000 SFP9 TR pistols and 450 SFP9 SK (subcompact) pistols were ordered in December 2017 with deliveries in 2018.
GSG 9 — As of 2018, the VP9 Tactical will replace the older Heckler & Koch USP Tactical.
State Police of Lower Saxony — Approx. 22,000 pistols will consecutively replace the former P2000 pistols.
State Police of Saxony — More than 11,000 SFP9 pistols ordered in 2015. (Deliveries will take place from 2016 to 2018).
State Police of Brandenburg — Approx. 8,000 SFP9 pistols replacing the P228.
State Police of Mecklenburg-West Pomerania — 5,700 pistols ordered.
Japan Ground Self-Defense Force - future standard issue sidearm, replacing the SIG P220 
Grand Ducal Police — Approx. 1,700 SFP9 pistols replacing the Smith & Wesson 686 as of 2017.
Phenix City Police Department, Alabama — 107 VP40 pistols will replace the department's Glock pistols.
City of Madison Police Department, Wisconsin — Officers can choose to carry an HK VP9 over other Glock offerings.
Whitehall Township Police Department, Pennsylvania
City of Tukwila Police Department, Washington
Clark County Sheriffs Department, Nevada — Approved as duty weapon
Cantonal police of Basel-Stadt — 900 pistols.