Yahoo! is celebrating its 15th birthday this week and it seems to be prompting a lot of talk about the internet, how it all got started and where it’s going. Did Yahoo start the internet?

Technology has fundamentally changed the way that marketers approach advertising. With the internet creating a new medium – digital – the marketing industry has changed forever, to which Yahoo was at the forefront.

Fifteen years ago, when Jerry Yang and David Filo had a lot of spare time on their hands, they decided that this internet thing was going to be a big deal and wanted to make it easier for people to navigate around.

When I think back to 15 years ago, I remember wondering what I’d ever need to know about the internet for. It was complicated and all scientific back then. Plus, the ‘www’ in my eyes stood for the ‘world wide wait’, I was impatient and would rather look up an encyclopedia than sit in front of an old IBM monitor listening to that terrible dial-up sound. My how things have changed.

Now there are 234 million websites, 200 billion spam emails per day, 126 million blogs and 27.3 million tweets per day. Yahoo alone has 600 million users, so I think a Happy Birthday is in order as just 15 years ago, there were only 18,000 web sites and fewer than 10 million people globally on the internet.

There are estimated to be 1.6 billion people on the internet today—about 25% of the world’s population.

In a blog posting, Yang and Filo wrote: “We’ve had the unique opportunity to help create an industry and shape the online world…always trying to invent the future. Of course, we didn’t set out to start one of the world’s largest internet companies or be leading a movement that has changed the world.”

 It is worth remembering that Yahoo was the first major search engine to enjoy success in the early days of the internet – it was around before Google, yet we never said ‘I Yahooed it’. It was also one of the only internet companies to survive the dot.com bust, which consequently sent its shares soaring.

But by the very nature of the internet, the online world evolved which meant competition and when you come in at the top, there is only one place to go. 

The huge lesson Yahoo has learnt in 15 years? Yang and Filo say: “Change and growth on the internet happen at warp speed—especially if you’re filling a need. With the proliferation of websites and with hundreds of thousands of people accessing our guide, it was simply impossible for us to continue doing this on our own.”

Yes, the lesson was to accept competition, and a few years later, defeat. But never fear, Yahoo will be around for a while yet. It has teamed up with Microsoft to make sure of that and had made headlines this week after signing a deal with Twitter.

Yang and Filo conclude: “The internet still has enormous and untapped potential.  There are billions of more people we need to drive online, and then provide them with relevant content and opportunities that they’ve never dreamed about before.”

Digital Britain minister Stephen Timms agrees and has set the government a target of getting 7.5 million more people online by 2014 with up to £12m allocated to spend on digital social inclusion.

 More info on how the internet has changed our lives from an interview with Yahoo.