Social news sites come to prominence largely over the controversies associated with people gaming them, and without people gaming them few would ever garner a critical mass. Marketers spamming a social news site is part of the growth cycle.

• Andy Hagans highlighted 17 social sites that send traffic.

• Some authoritative sites like CSS Reboot and Recruiting.com are powered by Pligg.
• You can find thousands of Pligg sites here, and find a few that are relevant to your industry by adding your keywords to this string. For example, business.

If I can come up with an easy search string to detect that many Pligg sites you have to think that as people and spambots abuse them, the search engines will discount most of their votes, but short and long term there is still going to be value to many of them.

Why buy low quality PR2 and PR3 links from inactive parts of the web when you can get on topic ones for free? Of course most of these communities will have limited value and die (failing to build a critical mass), but if you are submitting useful content to the real ones that will also lead to indirect links and other signs of trust and quality.

Content networks with virtually no content cost, free software, and limited editorial control might call people who submit self promotional stuff spammers, but what are all these sites until they build a critical mass? Parasitic useless noise, a form of spam.

The difference between a spammer and a contributor is that a contributor will post at least a few entries that are not self promotional, and they will also create content worthy of exposure. Both of which help build the community.

If you feel bad about gaming markets just remember that every market and every value system is both self-promotional and gamed.

As a background, here are some background tips on formatting linkbait and free linkbait ideas.