Not many people know this, but Google shows different results to different people – even if they’re searching for exactly the same thing! This is because Google personalises its results based on what it already knows about you.
The reason for this is to provide more useful and relevant content, and this is generally a good thing for searchers. But as a website owner, bear in mind that it might be artificially inflating your site’s own search engine position!
If you’re logged into Google then Google probably knows that you are the owner of your website. Even if you haven’t explicitly told Google that you are the owner of your website – for example, by adding it to Google Analytics or Webmaster Tools – then Google will remember that you have visited it many times in the past. This tells Google that it’s a website you’re particularly interested in. As a result, when you search for keywords related to your industry, Google will ‘helpfully’ display your website higher in the search results than if you’d never visited it before.
This can cause problems if you’re trying to assess how well your website is going in Google, as what you’re seeing isn’t what your customers are seeing.
See Google’s Turn off search history personalisation page for instructions on how to stop this from happening.