There have been more than a few debates and suppositions over the years about the potential value of linkbait/viral content strategies and whether search engines will always reward these practices. Today (actually, it's late at night here in Oslo), I wanted to tackle this debate and succinctly present reasons why I believe this methodology will remain powerful and effective in the long run.

First - a quick definition of linkbait as an SEO pursuit:

Linkbait/Viral Content: The practice of crafting web content to attract attention and awareness in the form of natural links given by bloggers, news media, researchers, forum posters and other website contributors. This content can include any combination of static or interactive elements, but is almost always targeted at a specific subset of web audience members who have the ability to influence/create links, share content and spread a message virally (see Linkerati).

Second - a peek at some infographics that help explain why this trend is so powerful:

(SOURCE: Forrester Research via the Groundswell Blog)

Just three years ago, those of engaging in linkbait were targeting 30-50% fewer people than today. That doesn't always mean it's easier (in fact, it may be harder, particularly on uber-popular viral sites like Digg & Techcrunch), but it does mean the opportunity to influence has risen dramatically.

So why do I feel so strongly that this carries little to no risk of penalization or devaluation?

1. Viral content is at the core of exactly how the engines want to operate. Search engines are, since their inception in the 1990's, attempting to use the web's link graph to identify content that people have found fundamentally interesting and worth sharing. Linkbait is exactly this - every link to a piece of viral content is created independently by individuals who think it's valuable enough to spread.
2. Devaluing "linkbait" carries an incredibly high "slippery slope" risk. Once could easily make the argument that every website is technically designed to be linkbait and thus, every natural link should be "suspect" (if linkbait was to be considered a manipulative tactic). The fundamental concept of product development for the web is actually based on the same principles as viral content - site builders are trying to make sites and information that people find compelling and want to use + share; penalizing this practice seems to contradict the very idea of the web's link graph.
3. Search engines have always touted that so-called "natural links" those that are independently created, editorially given and meant to serve as an honest recomendation for a URL's worthiness are the most desirable and positive kinds of links. This is precisely the type of link attracted by linkbait, in precisely this manner. Viral content is launched, promoted and hopefully seen by individuals who may like it enough to share it and link to it. There's little else on the web that can attract "natural" links.
4. Linkbait is "great content" - the very thing engines and engineers are constantly recommending as the core strategy for good SEO. To go against this principle would be to invalidate more than a decade of advice. When linkbait isn't "great" it tends not to attract links and the engines' work is done for them.

Like anything in the SEO world, there are higher and lower risk methods for engaging in this practice. Former SEOmozzer Matt Inman wrote a post highlighting some of the most dangerous implementations of manipulative link attraction, but these are most definitely the exception rather than the rule. A rough risk scale might look something like:

• No Risk - Production of relevant (on-topic with the site's offerings) viral content with no manipulative link schemes promoted ethically and organically on and off the web.
• Low Risk - Production of relevant viral content with potentially manipulative promotion (paying those with powerful social media accounts to help "push" the content into visibility).
  This is low risk in my opinion because the links are still created and given organically and editorially. Even if you manged to, for example, bribe Digg into promoting your story on the homepage, if that story attracts natural links from bloggers, writers, journalists, website owners, etc. it's still fulfilled the search engines' principles of high quality content that naturally derived editorial links.
• Moderate Risk - Production of somewhat "off-topic" linkbait that has only a loose thread tie to the content of the site.
  While I don't believe the links will be devalued, it's possible that they won't provide as much help to the other sections of the site or it's overall domain authority and ability to push up the rankings universally across the domain.
• High Risk - The combination of off-topic linkbait and manipulative push practices, possibly with other less-than-fully-honest tactics like highly manipulative or irrelevant anchor text pointing to the content's "sponsor" or "creator" (typically, this is fine to do, but when employing certain types of "off-topic" anchor text, you need to be carfeful).
• Extreme Risk - Creating content that attracts natural adoption of link code that recommends or points to something other than the original piece intended by the link creator. This could happen by crafting micro-sites on a topic, attracting links and redirecting them to off-topic, commercially focused pages/sites; embedding links into a "copy + paste this code" piece that visitors may not realize links to a location they didn't intend to endorse; etc.

You can probably tell that I'm a big believer in and supporter of viral content. I actually maintain a list of cool viral content projects that I'm impressed by, and I thought to end this piece, I'd share some of those:

• Viral Video Done Right
• 10 Facts Every Westerner Should Know about the Middle East
• A Visual Guide to the Financial Crisis: The Bailout
• Web Development Project Estimator
• Economic Recovery Dashboard
• Infographic of US Swine Flu
• Amazon Acquisitions and Investments Leading up to Zappos
• How Different Groups Spend their Day
• Military Spending Worldwide
• Information is Beautiful
• The Booze Death Calculator
• Tim Series of Reported Occupations in the US (AKA Job Voyager) 
• Online Dating Advice: What to Say in a First Message
• Modern Mugs and Creative Mug Designs

If you have differing opinions about how the search engines might treat viral content/linkbait SEO strategies, I look forward to chatting in the comments :-)