I've been thinking it's time for an "old-school" SEOmoz blog post. These are some of the rarer, but occassionally highly effective techniques for rooting out links in a challenging campaign.

#1 - Mentioned without a Link
This one is surprisingly effective. Your goal is to identify sites/pages that already mention your brand/product/service/website but have failed to provide the direct HTML link. Just shoot them a pleasant, personal email and request the link - success rates can be very high. To find these willing linkers, you can use Yahoo!'s advanced search parameters, i.e. "seomoz" -linkdomain:seomoz.org

 #2 - Profile Sites
All those "Web 2.0" sites that allow for the creation of profiles with links, from Frappr and Newsvine to MySpace and Yahoo! 360 to Digg, Del.icio.us and StumbleUpon are goldmines for links. Even those that don't have direct links enabled often allow you to submit sites or show what you've "tagged" or visited.

#3 - Can I Quote You on That?
If there's a particularly strong site in your sector that you desperately want a link from, this tactic can be of occassional use. The idea is to write a news article with some legitimacy and request a quote from the company/individual you want a link from. Once they know you're writing about them, make sure to send them a copy of the press release or story once it hits and let them know they're welcome to copy portions of the article for their own site if they'd like to reference it (with a link of course).

#4 - Friends & Family
I'm always shocked at how few people send a blast email out to their friends and family requesting links. You're guaranteed near 100% conversion rates for those folks who do have websites or blogs and it's a natural way of making connections - after all, these are the same people who'd recommend you at a party to their friends, so why not ask for the equivalent online.

#5 - Think Local
Sites from Citysearch & Yellow Pages to Google Maps (though that link doesn't count) provide global, local links if you sign up with them, but in nearly every mid-large metropolitan area, there are literally hundreds of directories and lists of local companies in every possible category. Oftentimes they're free and even when they aren't, the prices to be listed are fairly inexpensive. Try searches like seattle inurl:directory or "new york" intitle:marketing intitle:firms - obviously, it helps to get creative with your searches, but with so much opporunity, why wouldn't you?

Any "rare" link building tips you'd like to share?