My favorite Cameron with an unconventionally spelled last name (other than Cameron Frye in Ferris Bueller's Day Off), Cameron Olthuis, wrote a post on Search Engine Land called "5 Reasons to Put Viral Content on Mini-Sites." Now, obviously Cameron isn't arguing that you should always use mini-sites (aka a separate domain) when launching viral content--he simply posits that there are instances where using mini-sites is a good idea. (Apparently 37% of "very experienced marketers" agree with him, as, according to an eMarketer.com study, about 1/3 think that "cool microsites" produce great results...though I think the percentage doesn't seem that that high.)

Fine and dandy, Cameron. I thought, however, I'd remind everyone why you wouldn't want to split content onto mini-sites (once again, this isn't a dig at Cameron's article, it's just here to complement/bookend his points):

1. You run the risk of sandboxing a new domain, meaning there's a chance the content won't rank at all. I'm not saying this will happen every time, but chances are the new domain won't be as strong as the original domain.
   
2. You're not getting all that nice, new traffic to your main domain.
   
3. You're splitting link value, meaning...
4. ...you're not helping your main content rank better; instead, you're now tasked with ranking two sites well.
5. Users may not get the connection. If your company has a super-rad viral thingamabob that you put on a separate site, people might go "Cool!" without ever putting 2 and 2 together, that it is your company's product/brainchild/whatever.

Of course, you can still register a separate domain for a viral marketing launch and then just 301 it to your main domain. We did just that with the Web 2.0 Awards (coming next week, we promise!)--initially, we launched the awards on a separate domain, web2.0awards.org. After a while, we 301'd it to seomoz.org/web2.0, which brought SEOmoz a healthy 100k+ backlinks. Now we rank (I'm seeing 11th) for the term "web 2.0," and we receive a good amount of traffic from it every day.

Obviously, Cameron's five reasons for mini-sites and my five reasons against them combine to form a superset of "It's a judgment call." Wildly successful viral marketing launches have kicked the crap out of my five reasons, while smaller, less successful launches may have learned to keep such tactics on their main domain in the future. I'd be mindful of both the risks and the rewards, and decide for yourself what's more worthwhile.

That's about it. I'll close with the following:

When Cameron blogged at Search Engine Land...let my Cameron...gooooooooo.

Long live Ferris Bueller's Day Off.