In the beginning, Google was a postgraduate research project from Larry Page and Sergey Brin. When it launched in 1997, Google's search rankings were based predominantly on the number of inbound links to your site, as it calculated the probability of a web page being stumbled across in a random search.
By 2000, Google was the world's largest search engine, indexing more than 1 billion web pages. But as content on the internet exploded, so did users' expectations of Google's performance - and they quickly had to adapt to meet changing needs. In 2001 image search was launched, and by the end of that year Google's index had grown to 3 billion web documents, and it was answering more than 150 million searches each day.
However, at this time Google was still indexing pages up to one month in advance - so when the news of 9/11 broke, Google couldn't give users the information they were looking for in real time. This was the catalyst for Google News, which launched in 2002. The demand for multiple types of content grew and grew, and by 2004 there was shopping search, news search, image search, book search and academic search with an index of more than 8 billion items. Video and blog search were added in 2005. 2006 saw the introduction of patent search, and in 2007 Google announced their vision for Universal Search - all types of content, all in one place, ranked in order of relevance.
The next significant development that affected search from a marketer's point of view came in 2008 - the social media industry had exploded and with it came social search, which added relevant content from your friends and contacts to your search results. Then in 2011 another breakthrough - rather than searching for different types of content, users are now able to search BY image or voice - and as the use of mobile technology grows in subsequent years, voice search becomes increasingly important for marketers to consider as part of their SEO strategy.
If you'd like to know more about the history of search and how it works, check out Google's Inside Search site, with a great timeline here.
What does all that mean for my SEO?
In a nutshell, it means you need to move with the times. The way you approached SEO five years ago, or even last year, isn't going to get results in 2016. Search engines assess more than 200 different factors to rank your site, and as search gets more complex, so should your efforts to influence it. So here's what you need to consider to get your website to page one right now:
1. Keywords still count
Although keyword stuffing and writing web pages in a way that is designed to get them found is now a pointless task, using keywords relevant to your audience still matters. Use Google AdWords to help you identify what those keywords might be - and consider the way search is changing. When someone asks Siri, they use different search terms. The most recent stats I could find, from October 2014, showed 41 per cent of adults use voice search at least once a day. Through voice search, users are more likely to use long-tail keywords (because it's quicker to talk than to type) so make sure these are included on your list.
What is a long-tail keyword? A four or five-word phrase that's very specific to your content. For example, if you're a florist you won't come at the top of a search result using "florist" because there is too much competition. But with "wedding flowers delivered in Oxford" you stand a greater chance.
2. Optimise content, not just pages
Content marketing is a big business right now. For years I've been going to conferences where everyone is saying marketers are missing a trick if they're not using video. This is true - but using varied content isn't enough - for search engines to crawl that content you need to make sure it is optimised. Use proper tagging and metadata on everything on your website, not just your landing pages.
3. It's all about trust.
If you've read my blog before, you'll have seen that I believe authenticity is the most important factor in business growth. Well it turns out Google agrees. Site and page quality is a big influencer of search rankings - you have to prove you're trustworthy, reputable and relevant in your industry. This means providing regular new and relevant content to your audience (rather than a static old website), which people want to link to. Those inbound links, from authoritative websites, are Google's indicator of your trustworthiness. Think quality, not quantity.
Entrepreneur.com have published an interesting article on TrustFlow and SEO here.
4. Think local, NOT global.
Another key factor for Google is user context. It will deliver search results based on a user's geographic region and web history - so make sure your business is listed on Google for higher visibility in search engines and optimise for the regions you operate in.
5. Be a social butterfly
Don't forget that social posts get ranked higher. Your social media strategy isn't only important for expanding your reach, it's important for SEO too. Put some effort into your social media profiles, with regular relevant and timely updates, and get your LinkedIn, Twitter and Facebook pages on the first page of Google as well as your website.
Do you have questions about how to 'do' social media? This blog is a good starter for ten.
And finally... If you're not mobile optimised, you don't stand a chance. Google's algorithm update in April 2015, dubbed "mobile-geddon", downgrades sites that aren't for all mobile searches - and since around 60% of online traffic now comes from mobile devices, that's a big piece of the pie you're missing out on.
Read more on where to focus your marketing efforts in 2016 in this round-up of mobile, SEO and social trends from Smart Insights.