How old is digital marketing industry?

With digital marketing wholly reliant on connectivity between electronic devices, it's closely tied with the world wide web. On that basis it could be argued that digital marketing started in 1991, alongside the launch of the web, making it 25 years old.

The first ever recognised digital ad and advertising campaign launched on HotWired.com, on October 27 1994. If you use this date, as many do, then the digital marketing industry is 20 years old.

The phrase 'digital marketing' was definitely first used in the 1990s, either way.