Being thin may have its advantages offline, but online its a dirty word. Google gives a rating of offensive to thin affiliates, the ones that simply duplicate other sites send traffic to the second site, earning affiliate commissions with no value added content or services. If a site isnt unique or helpful and just acts as a middleman, adding nothing to the buyers decision process or the sales process, it is called a thin affiliate or an affiliate doorway.

What do thin affiliates do that put them on the bad side of Google.and what Should you NOT put on your site?

Links overwhelmingly pointing to one affiliate merchant it begs the question, why not just go there first?

Images located exclusively on another site

Pages of almost zero content that house PPC ads

Affiliate merchant data feeds

Hidden links

Keyword stuffing for search engine bots, with text no human could comprehend

Hidden text such as white text on a white background, loaded up with keywords

Content or images displayed only on pop-ups

Ads displayed to look like search engine results

The bottom line is that if you are considering anything that will have the effect of looking different than it is, easily misleading someone, technically tricking search engines, or profiting on the back of someone else, forget it. You do so at your own peril and the peril of your site. This isnt the wild west anymore. Legitimate companies base their livelihood on fair and honest dealings on the web, and those who dont subscribe to honest practices will be left in the dust.