Quality, Niche Directories Are a Safe Bet
In this post-Penguin era of internet marketing, it's no wonder people are cautious when it comes to link building. Judicious and careful link building has alway been good practice regardless of what kind of updates Google make to the way they rank sites, and part of your link profile should include quality, niche directories that have a rigorous editorial process.
The Four Keys To Post-Penguin Directory Submission Happiness [searchengineland.com]
We go even further than provide a quality, niche directory - we publish our review notes and show the reasons why we've listed each website in our directory. We reject between 60% to 75% (depending on time period we measure) of submissions we receive - there's a lot of sites you won't see listed in our directories simply because they don't meet our strict guidelines. We also remove sites that no longer exist, or 301 redirect to an irrelevant new site, or simply change their content to such a degree they no longer are a relevant listing in our directory. Having said that, if you are a genuine business with good signs of trust on your site (that we carefully look for), then you can be reassured that we would be happy to include you in our directory.
More References In Regards to the Importance (and Safety) of Quality Niche Directories
"Many paid directories continue to be good signals of authority, due to the cost of entry that pays for their editorial reviews that help ensure quality. In particular, vertical and niche directories can be high quality, but you should steer clear of those that are covered in ads and donít have an editorial review process."
Link Building Best Practices In A Post Penguin Era [weidert.com]
"The days of seeking out and applying to every directory on the web for an inbound link are over. It's important to stick to high quality, notable directories and niche directories that are specific to your industry."