Now, even this process is starting to be manipulated. Some webmasters are creating pages that look nonsensical to people but have just the right frequency of words to fool an indexer about their subject. Webmasters make thousands of these pages that differ enough to make the indexer think they are unique, and all point to the one that the webmaster wants you to see. Again, porn sites are big fans of this tactic. These latter tactics fall into the grey area between aggressive self-promotion and scamming.
Search engines try to stop it when they can.
The search for the perfect solution is still on.