Making Sense of Steam‘s Secret Sales Numbers

As an industry analyst and avid Steam gamer, one of the most common questions I‘m asked is: can you accurately estimate unit sales for games on Steam?

Unlike boxed retail games, Steam does not share official sales data with the public. The actual number of units sold behind the scenes remains closely guarded. Still, some clever detective work allows us to make reasonable estimates.

In this comprehensive guide, I share professional techniques to shine light on the secretive world of Steam sales figures.

Leveraging Steam Reviews and Ratings

Reviews and ratings offer a useful correlation to sales, despite not always being accurate. Generally, the more reviews a game has, the more units it has shifted.

For example, the overwhelmingly positive rated indie hit Stardew Valley has sold over 20 million copies according to its developer Eric Barone. Is it pure coincidence that the game also has 324,000 reviews? Unlikely.

Of course, allowing for players who don‘t leave reviews, we can assume the total sales are higher than the review count. But it offers a baseline indicating multi-million sales.

By comparing review counts between games in a genre, we can also estimate relative performance. For example, survival crafting game Don‘t Starve has 62k reviews while Stardew Valley has 324k. Indicating it probably sold around 5x less units.

Leveraging SteamSpy and Ownership Data

SteamSpy aggregates public data from Steam user profiles to estimate ownership counts for games.

For example, SteamSpy estimates Stardew Valley ownership between 10 and 20 million players. A figure much more precise than reviews alone.

However, SteamSpy relies on sampling public profiles so lacks perfect accuracy. The site itself claims a 10-20% margin of error.

Still, for ballpark estimates, SteamSpy offers valuable data, especially for seeing sales growth over time. The chart below shows rising Stardew Valley owners according to the site:

Pay Attention to Publisher Sales Announcements

Occasionally publishers will announce major sales milestones e.g. 1 million units sold. This at least confirms a baseline of units shifted.

For example, Paradox announced that Cities Skylines sold over 9 million copies across all platforms. While not Steam specific, it shows the massive success of the city builder.

Though publishers rarely give exact unit breakdowns between platforms like Steam vs. PlayStation. So announcements still only reveal part of the picture.

Track Achievement Unlock Percentages

Steam achievements unlock percentages offer hints at total players.

For example, if 80% players unlocked the "Stardew Hero" trophy awarded an hour into Stardew Valley, it suggests around 80% of owners actually booted up the game.

Whereas niche games sometimes have 50-60% of achievements unlocks because there are fewer active players relative to copies sold.

This method isn‘t foolproof…achievement difficulty impacts percentages. But it can separate smash hits with mass appeal from games with ownership inflated by Steam sales bargain bin deals.

Analyzing Engagement Data

Metricstracking concurrent players, Twitch streams, Community Hub members etc. reveal current engagement. Activity often correlates with sales.

For example, Stardew Valley avg. players per hour tripled from 2020 to 2022, suggesting massive YOY sales growth:

Though solely current engagement doesn‘t always indicate lifetime sales as evergreen titles stay popular for years. So this data complements rather than replaces other estimates.

Paying Attention to Industry Analyst Estimates

Reputable industry research firms like SuperData occasionally publish wider market reports with steam sales estimates by title.

For example, this SuperData chart reveals their forecast lifetime digital revenue for major Steam games as of early 2020:

Their analysts use proprietary methods leveraging publisher partnerships to model Steam Market performance. Respectable methodology but still not 100% perfect.

Making Back of the Envelope Calculations

Taking an analyst approach, we can combine data inputs to produce back of the envelope forecasts.

For example Stardew Valley:

• 324k reviews
• SteamSpy says 10-20 million owners
• Recent ascendance as top Steam game by playtime
• Developer fixed price point since launch

We could logically estimate 15 million lifetime sales as of 2023. Potentially conservative given the current popularity surge.

Though the confidence interval is wide, it contextualizes success rather than relying on peaks at revenue or player count that misrepresent sales.

I‘ve showcased a range of analytical techniques experts leverage to shine light on the opaque world of Steam sales figures.

While no perfect 100% accuracy fix, combining indicators allows reasonable estimates and valuable market intelligence. We can surface hidden success stories, analyze market positions and performance factors allowing smarter decisions.

Next time you wonder about Steam sales for a particular game, consider employing a few of the methods above before asking Gaben for his internal data!

What techniques do you find yield useful insights? Let me know in the comments below.