Bots don't vote as far as I know. They just "grab" the info on your site, and most do so with your permission.

The voting is done by the internet it self. Internet being everybody that participates in one way or another in the internet.

Search engines interprete these votes the way they see best for the quality of their search results. And the ones like Google can give a bit of that eMoney (Adsense).

Why do you think that some search engines see your sites as a link farm?

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