“I think there is a world market for maybe five computers” is one of those infamous predictions, attributed (but probably falsely) to Thomas J Watson, chairman and CEO of IBM in the 1940s. Its survival owes less to its veracity or context, and more to the fact that we all recognise a kind of truth in it: that we all underestimate the impact of technology in the long run. (Twinned with “and overestimate it in the short run”, this is known as Amara’s law, and is definitely attributable to Roy Amara, one-time president of the Institute for the Future).

It’s funny to laugh at these things now, but important to remember that they often have real effects, which shape how we understand the world. When the internet’s domain system originated, it was thought that all we would need would be six top-level domains (TLDs) – .gov, .edu, .com, .mil, .org, and .net – and country codes. In the past couple of years, this system has finally given way, and new domains are available every day – recent additions include .dentist and .kitchen. The URL has ceased to be an address and become a descriptor.

Two weeks ago, perhaps inevitably, Amazon purchased the .book TLD. In a private auction among nine companies including Google and publisher Bowker, Amazon is reported to have spent somewhere between $5m and $10m to have the right to control and sell all addresses ending in .book. As the traditional URL disappears – most people just type “Facebook” into Google, rather than writing the address, for example, it seems likely that signifiers such as the TLD will come to assume a greater authority – particularly when one company owns the whole stack. Ten million dollars for four letters and a full stop might seem like an overestimation now, but perhaps we should start paying attention to Amara.