- Google analyzes somewhere around 200 different ranking signals. At least that was in 2009. It’s probably more today. Most of these ranking signals are pretty well known, but there is still some significant argument within the community about many of them.
- Each Google ranking signal may carry varying degrees of weight and importance, any of which may be tweaked, improved, degraded or removed at any time. Google is constantly rolling out algorithm tweaks and changes, adjusting the signals or even adding or removing them as they feel the need. While these changes may not be major, they can – and do – have an effect on how pages rank.
- There is no one single Google algorithm. In fact, at any one time there may be anywhere from 50-200 different algorithms at work. These different algorithms might be in play for different industries, different types of searches or testing the effects of various algorithm changes before a full push.
- Panda and Penguin updates are not updates, but filters that they periodically run their index through. If your site got hit with these updates, fixing the problem that caused it won’t bring immediate results. You have to wait until the next time Google runs the filter.
- The zip code you are searching from can have an impact on your search results. Google tries to determine which queries are geographical in nature and deliver results most relevant to your particular location. The same search from a different location will produce very different results.
- Google has been working personalization into the search results for some time. If you’re logged into Google, it’s keeping record of your search history and sites you typically click on. The more information it has on your preferences, the better it is able to deliver results to your liking – or at least what Google thinks is to your liking.
- Adding a new twist to personalization are your social signals. Google is now personalizing results based on who you are connected with (in Google+) and pages they may have +1’ed. That means your “friends” are directly influencing which sites you see when you perform a search!
So what does all this amount to? Well, it means that the results you see may or may not be a reflection of the Internet at large. If you see your site come up #1 in the search results for your keywords, that might simply be a result of your own personalizations, localizations or socializations. If you turn all those off and you’re still in the top spot, you likely aren’t for a lot of other searchers that are getting results based on their own personalizations, localizations and socializations.