How many copies did WWII Online sell?

91k to 148k copies, based on its 4k Steam reviews. This is a labeled estimate from the review count, not exact sales.

How much revenue did WWII Online make?

WWII Online is free to play, so there is no copy-sales revenue to estimate.

How big is WWII Online?

Estimated owners: ≈ 91k–148k; from 4k reviews (Mixed)

A labeled estimate from the public review count (adjusted for release year), not exact sales. Owner data cross-checked with SteamSpy.

Does this actually work?

We left WWII Online out and predicted the genre from its 8 similar games. Every figure here, including WWII Online's, is estimated from Steam reviews, not self-reported sales.

Copies, estimated from reviews

typical (middle half) 428k–987k

best case 52.4M (War Thunder)

The Flight genre

All 8 of your similar games are hits. A healthy genre for a game like yours.

A hit here: 1,000+ reviews, roughly $150k+ before Steam's cut (a standard indie benchmark).

A typical game

≈ 428k–987k copies

≈ $4.8M–$13.5M after Steam's cut

from ~10k reviews

Best case

≈ 40.0M–64.9M copies

War Thunder

A breakout hit, far above a typical game.

The genre you'd be entering

Your set: Your set clusters on Flight (6 of 8) and Simulation (6 of 8).
The winners: Winners here lead with Simulation + Vehicular Combat. The breakout hits carry Vehicular Combat + Combat + Free to Play; a typical game here doesn't.
The era: The games you compared span 2012 to 2022, a genre with a long track record.

Copies and revenue are rough lifetime estimates from the review count.

Similar games

Game	Est. copies	Est. revenue	Price	Reviews	Tags
War Thunder 2013	Est. copies ≈ 40.0M–64.9M 78x vs typical SteamSpy 20M–50M	Est. revenue Free	Free	768k reviews Mostly Positive	Free to PlaySimulation
Ace Combat Assault Horizon - Enhanced Edition 2013	Est. copies ≈ 272k–443k SteamSpy 200k–500k	Est. revenue Free	Free	5k reviews Mixed	ActionFlight
DCS World Steam Edition 2013	Est. copies ≈ 2.1M–3.4M 4.1x vs typical SteamSpy 5M–10M	Est. revenue Free	Free	41k reviews Very Positive	SimulationFlight
World of Warplanes 2022	Est. copies ≈ 135k–219k SteamSpy 1M–2M	Est. revenue Free	Free	6k reviews Mixed	FlightFPS
STAR WARS™: Squadrons 2020	Est. copies ≈ 741k–1.2M 2.9x vs typical SteamSpy 1M–2M	Est. revenue $8.1M–$21.9M after Steam's cut $14.8M–$33.7M before the cut	$39.99	28k reviews Mixed	FlightSpace
X Rebirth 2013	Est. copies ≈ 380k–618k SteamSpy 500k–1M	Est. revenue $3.1M–$8.4M after Steam's cut $5.7M–$13.0M before the cut	$29.99	7k reviews Mixed	SimulationSpace
Guns of Icarus Online 2012	Est. copies ≈ 763k–1.2M SteamSpy 2M–5M	Est. revenue $1.0M–$2.8M after Steam's cut $1.9M–$4.3M before the cut	$4.99	15k reviews Very Positive	SteampunkTeam-Based
IL-2 Sturmovik: Battle of Stalingrad 2014	Est. copies ≈ 512k–832k SteamSpy 200k–500k	Est. revenue $7.0M–$18.9M after Steam's cut $12.8M–$29.1M before the cut	$49.99	10k reviews Mostly Positive	FlightRealistic