This causes a lot of confusion. Why is it that when you search for your main keyword your website comes up, but when your best friend searches on their computer your site isn’t even in the top 10?
Google & Bing’s success as search engines rises and falls upon whether or not they give you the most relevant results. They want to keep you happy, so you keep using their search engine.
Over time, they’ll see that you visit particular websites all the time, or that you favour news over static sites, that you live in Australia, so events in the UK are less relevant. They’ll then take that information and tweak the search engine results they deliver to you.
If you search for “café” the search engine can figure out that you’re looking for a café in your town, not in New York. After a while, they might even skew your results towards your favourite local cafés.
It does this through a combination of saving your web search history (you probably didn’t uncheck that box when you signed up for a google account, did you?), your browsing history (particularly if you use Chrome or IE), many of your web interactions if you’re signed in to your Google account, your Twitter interactions and possibly your IP address (your computer’s address on the internet) – but I can’t verify the last because I’m on a dynamic IP that changes every week or so. It’s a handy feature for a lot of people, but it can make you overly enthusiastic if you’re trying to find the rank for your own site.
The problem arises because you go to your site all the time to update it, walk clients through parts of it, check everything’s working, etc. As a result, Google and Bing see your site as highly relevant to you. Hey, they’re only machines!
So if you run a wedding site and search for Perth wedding venues, your site is naturally going to be ranked far higher in your results than in the “standard results”.
With the rise of personalised search, especially Search Plus Your World, search results are becoming increasingly less standardised. However, they are very useful for establishing a baseline. A starting point, if you will.
Personalisation is only going to mess with the results to a certain degree. If someone is searching for information or a product in an area they haven’t searched before, your high baseline results will do very well. Also, if you have a high baseline, you increase the chance that people will pass around the link to your site on social media, which will increase your ranking on personalised searches for those people and their followers & friends.
How To Fix
My way is to keep a browser (Safari, because I’m on a PC) completely clean. I never sign in to my Google accounts on it, I never click any search results and I never browse using Safari. The only thing I use it for is looking up rankings. This is especially useful when talking to clients on the phone, because I don’t have to fire up any complicated tools to check results. In my opinion, this is the best and easiest way. If you need all your browsers (particularly if you’re a website designer), just get another one. Maybe Opera. Just keep something free from interference.
If you absolutely have to use your main browser to check rankings, make sure you log out of any google accounts, log out of Twitter & Facebook and clear your browser’s cache & cookies.