In the past, search engines looked primarily at meta tags. When people began "spamming" search engines, or repetitiously placing keywords in meta tags and page text so they could pull poor sites ahead of good ones in search ratings, the search engines changed their formulas (and continue to do so) to push spamming sites down and bring worthier sites up. If, however, you are truthful with both the spiders and your customers, you can achieve decent rankings.
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