In order to achieve maximum traction with your Citation Building efforts I believe that you need to focus on the following:
1. Complete and verify your NAP on Acxiom, Localeze, Infogroup.
2. Claim, verify and enhance your Google local isting/s, the one on Bing, and Apple Maps.
3. Go over your business profiles on Facebook, Twitter.
4. Claim and verify your listings on Yelp, YellowPages and on those directories, which require phone verification.
Then perform a quick audit (you can use some of the free online tools out there). If you use a predefined list of relevant directories, make sure to go down the list in descending order in terms of source quality.
There are a lot of lists of directories out there. Most of the 3rd party directories are regularly crawled by search engines.
Local Business directories (especially the ones that are spam free) should be in your radar to get your business listed.
Industry-specific directories are also of great value for your local business, so don’t omit them.
As it comes to your question regarding quality vs quantity: it usually depends on the location and the specific niche that the business specializes in.
If you’re hardly facing any competition and you operate in a small city, then submitting your business to the key ten directories should do the trick and give you the competitive edge you need to rank in the local pack.
In other words, all factors being equal (which is hardly ever the case, but if we image it for a moment), a business with more and also relevant citations is going to appear higher in the search engine results as compared to a business with fewer citations.
For companies (such as WhiteSpark, BrightLocal) that have compiled lists of more than 1000 sources, it is important to keep into account that all of those sources are not meant to be used on a single business but rather are the total number of directories for different niches, locations, etc. Of those 1000 a business could get up to 100-120 relevant citations in total at best.