The long and short of it: In the first seven months of 2017, Spotify added a very impressive 12m paying subs to the 48m who were officially shelling out for the service at the close of last year.
At an average of just over 1.7m additional subscribers per month, this rate of growth would see Spotify finish 2017 with 68.6m paying customers – a jump of over 20m people year-on-year.
However, this is a conservative forecast: In 2016, Spotify added significantly more subscribers in the second half of the year (+12m) than it did in the first (+8m). And the same pattern applied in 2015 (H1 2016: +5m; H2 2016: +8m).
In addition, we know that Spotify is picking up pace in 2017: it added 10m subscribers this year between early March and the end of July – an average of over 2m per month.
If it can continue this 2m-per-month velocity, Spotify will add another 10m subscribers before the end of 2017, finishing the year with 70m.