The Many Faces of Hidden Text

The approach of using hidden text to try and improve a website's search engine exposure is as old as the hills, or at the very least as old as Google.

Basically, this tactic involves anything which hides a web page's text from a human visitor by blending it into the background, putting it behind an image or even telling the browser to display it offscreen.

At least that's the way a lot of SEOs see it, which is why they use hidden text to present human visitors with sleak, sales-orientated web pages, while still showing search engines the content they want.

How is it done?

Well? You didn't actually expect me to show you some examples of hidden text on this page, did you?
Let's just say that there are many and varied ways to hide text from visitors while leaving it perfectly viewable to search engines. Back in the olden days all a web designer or SEO had to do was to set a web page's font the same color as its back ground, or put the text out of view behind an image.

But Google and the other search engines soon wised up to these techniques, and began to penalize websites which employed them, so some SEOs began to use external CSS files to make it harder for search engines to spot their shady tactics. Predictably, search engines soon caught up with them.

Nowadays, efforts at hiding text involve telling the visitor's browser to display text off the left side of their screen, thus placing it somewhere no human eye can reach it.
Google is on the case and will detect that too... just like it always does...