Google want their search to be the best. Arguably, it is. They do this by constantly reviewing and improving the criteria they use to decide whether a page is going to rank highly in their search results, and there are a huge number of things they take into account.
The reason they want to be the best, in very simple terms, is that the more users their services have, the more willing companies are to pay for advertising.
It’s not just Google, of course: Microsoft’s Bing is their biggest competitor at the minute.
I’ve blogged before about the things search engines use to rank a web page for a particular search and—two and a half years later!—the principles still hold true. If you’ve got a well built, well thought through website with great content and you market it well you’re on your way to top marks from Google and Bing.
The number of criteria search engines use to decide whether a page is going to rank highly in their search results or not is huge, and the specifics are never made public.
There are always people looking to game the system in order to get their site ranked higher than it really should be, but Google and its friends do everything they can to stop this. If a website has cheated its way to the top it’s not going to be a genuinely useful result, so searchers may defect to a rival search engine in the hope that they’ll get a better result there.
Each major update causes a lot of disruption for businesses that have tried to gain an unfair advantage and generally benefits those with great websites with great content!
The point is, even though Google and co. may announce a major update to their search engine, nobody really knows exactly what factors they rate as the most important and which will do your site more harm than good.