When Fallout Shelter was surprisingly announced and launched within one E3 2015 press conference, it was seen as something of a marketing ploy for Fallout 4.
With the much anticipated console/PC blockbuster not due for release until later in the year (10 November), Fallout Shelter would be a daily reminder that would drive pre-orders and mindshare in the meantime.
How well it's done in this regard is unclear, although Fallout 4's commercial and criticism is undeniable.
But in this week's Charticle, we're reversing the question and asking if Fallout 4's launch had any impact on Fallout Shelter's grossing performance.
Power of updates
The first thing to point out is that Fallout Shelter itself has been a massive success.
Despite lacking much longevity at launch, the game has remained in the top 100 grossing chart for iPhone in key markets such as the US and UK since its June launch.
And for a good portion of this time, it's been a top 50 grossing game too, although it was slipping down during September and October.
Looking specifically at the 10 November launch of Fallout 4, we can see that following its October updates (one content and one bug fix: neither related to Fallout 4), the game jumped back into the top 50 range.
This led to a clear spike in chart position - roughly from around the top 50 position to a top 20 position - when Fallout 4 launched.
This sort of movement is important, but what's also clear is that post-Fallout 4-launch, the game settled back to its previous top 50 range.
Yet given that the game was slipping out of the top 100 in the UK and US during October, Fallout 4's launch, combined with the update, appears to have rebooted and stabilised the games's top 50 position; a significant move.
Best in the west
If we look at some other key European and English-speaking markets, the trends are similar.
Fallout Shelter launched strongly on iPhone, slipping down into the top 50-150 range during August, before a content update kicked it back into the top 50 in Australia, Canada, France and Germany.
The October updates refreshed the game back up the charts, although back not into the top 50 grossing positions, except briefly in Canada.
Fallout 4's launch certainly had an impact in all four countries, although this was more short-lived than in the US and UK, with the Fallout Shelter then slipping down into the top 100 - top 150 range.
Play Store power
Because of the way Google calculates the Google Play charts, they are always much smoother than iOS.
This makes the analysis of Fallout Shelter's performance on the platform simpler.
The game launched on Android two months after its arrival on the App Store. But in all six western countries, it's seen a very strong success on the platform - even more so than on iOS - at least in terms of chart position.
As we've seen before, the October updates arrested a chart decline, with Fallout 4's launch boosting the game's grossing chart position significantly so it was back, well within the top 50 in all six countries.
Since then, however, Fallout Shelter has slipped back to roughly its pre-Fallout 4 launch position.
Given the strength of the Fallout brand in the west over many years, especially on PC, it's no surprise that Fallout Shelter hasn't appealed at a similar level in Asia.
It launched within the top 100 in Hong Kong and Thailand in terms of Google Play top grossing, but not within the top 150 in the competitive and lucrative Korean market.
In all three countries, it hasn't maintained that launch position, with Fallout 4 providing a minor boost in Thailand, but not doing anything significant in Hong Kong or Korea.
Looking at the iPhone top grossing chart in Asia, and the situation is the same.
Fallout Shelter launched into a top 300 grossing position in the key Chinese, Japanese and Korean stores, but quickly fell away, with Fallout 4's only having an impact - at least in terms of the top 300 - in Korea, and that being a very minor boost.
Given the amount of marketing and comment surrounding the launch of Fallout 4, it would have been a surprise if it had had no impact on the grossing position of Fallout Shelter.
However, that impact has been fairly minor in most countries, and quickly evaporated.
Instead, as demonstrated by the October updates which reversed Fallout Shelter's declining grossing position in key markets with additional content, it's been Bethesda and developer Behaviour Interactive's focus on game-as-a-service and the day-to-day operational support of Fallout Shelter that is the real engine behind the game's surprising top grossing longevity.