And today Ek did just that:
40 is the new 30.— Daniel Ek (@eldsjal) September 14, 2016
He was, of course, referring to the number of paid subscribers the music streaming service has.
It's a big number - but it's important to take into account that just one year after its launch, Apple Music has declared it has 17m (11m in its first month), and Spotify has been around for a decade.
To be fair to Spotify, the market for music streaming has becoming increasingly crowded since it launched in 2006. Not only has Apple Music cropped up, but musician-backed Tidal and Google's Play have both muscled in on the market - while Amazon is expected to launch its own version as soon as this month (although, to be fair, it may be distracted by today's European launch of its Echo virtual home assistant).
In May this year the company, which isn't listed, reported an 80 per cent rise in revenues in 2015, which hit €1.95bn (then worth £1.5bn).
But losses widened as it spent millions fine-tuning its technology platforms in order to compete with Google. That included heavy investment in features such as Spotify Discover, which generates personalised playlists for users.
"We believe our model supports profitability at scale," it insisted at the time.
"We believe we will generate substantial revenues as our reach expands and that, at scale, our margins will improve. We will therefore continue to invest relentlessly in our product and marketing initiatives to accelerate reach.” Hold tight.