I have two other theories:
1) When people search for something like dannon yogurt google records that donnon might be related to yogurt. Then later, when there's enough people having searched for that combination, Google gives a small weight to the word "dannon" occurring on a page, even when only yogurt is searched for.
2) When dannon and yogurt are mentioned together in close proximity yoghurt in a page the spider is crawling, the word "dannon" gets extra weight, even when just yogurt is searched for.
I reckon that Google uses all three of these measures as well as various traditional measures and weights them based on trial and error + common sense.
Oh, and by the way, dannon doesn't even get first page for yog_h_urt.
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If that's what they do it's bloody impressive.
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I have two other theories: 1) When people search for something like dannon yogurt google records that donnon might be related to yogurt. Then later, when there's enough people having searched for that combination, Google gives a small weight to the word "dannon" occurring on a page, even when only yogurt is searched for. 2) When dannon and yogurt are mentioned together in close proximity yoghurt in a page the spider is crawling, the word "dannon" gets extra weight, even when just yogurt is searched for. I reckon that Google uses all three of these measures as well as various traditional measures and weights them based on trial and error + common sense. Oh, and by the way, dannon doesn't even get first page for yog_h_urt.