I see that @rythie has commented on the HN discussion about this, and commented that “More than half of all the businesses have no employees (i.e. It’s just the founder) and most of the rest have less than 50 employees.” In the UK, ~80% of companies have no employees.
As someone helping to grow an SME, this is data close to my heart. Table A in Business population estimate for the UK and regions: 2015 statistical release (from Annual business population estimates for the UK and regions in 2015) says that of 5,389,450 registered UK companies, 4,077,590 have no employees and 1,068,815 have 1-9 employees (I suspect the vast majority of these have one employee). There are 203,525 in the 10-49 employee bracket. That leaves 39.5k companies in the >50 employees bracket.
So, Joel getting to 80 employees (I know he got beyond that then retreated) is an amazing achievement for a Warwick grad armed with a PHP script and chutzpah.
Actually my point in context (https://news.ycombinator.com/item?id=13616123) was that Buffer is a tool that has customers who are probably quite small in size and therefore don’t have dedicated communications/social media staff. In general, there is a big market of these small businesses to sell products to, since they typically can’t create their own tools.
Though your point is also interesting way of measuring their success. They’ve clearly achieved a phenomenal amount.