Facebook has recently made great strides in sharpening its advertising options and better targeting its ads. Eager to compete with Google for precious online advertising dollars, Facebook is working hard to use its tremendous wealth of personal information to help businesses better reach potential clients.
Within this general theme, there are two specific ways that businesses can now better target their advertising.

1. Custom Lists
Facebook Ads can now be shown exclusively to a customized list. This list, created by the advertiser, can simply be a list of email addresses or phone numbers. Once this list is created, Facebook allows your to target advertisements to the Facebook accounts associated with this information, even if their email or phone number isn't publicly available on Facebook.
This has created a situation in which companies can input contact lists, lead lists, email subscribers, or even cold leads, and then constantly check in on them with a Facebook advertisement. This obviously allows for a highly targeted ad campaign, in which you spend money on clicks from the right communities and you don't waste your budget on mismatched advertisement impressions.

2. Retargeted Ads
One of the reasons that Google had previously pulled so far ahead in advertising revenue was due to its sophisticated Remarketing ad options.
With remarketing, Google display ads could be shown to anyone who had previously been on the advertisers website. This meant that an entire ad campaign consisted on ads that appeared only for those who were already interested in or exposed to your product or service.
Facebook has caught up in this regard. Facebook Retargeting allows online marketers to place a line of code on their website, thus using cookies to compile a list of everyone who has been on the site. Facebook then advertises to the corresponding Facebook accounts of the people on this list.
These Retargeting lists (essentially a particular kind of Custom List) can be made as sophisticated as you'd like. Some create specific ads for specific pages and products. Others stick to a general ad.
This service currently only exists with Facebook Exchange and you need to go through a third party agency. This will likely change soon, but for now AdRoll, Perfect Audience Retargeting, and Triggit offer free trials.

Facebook for online stores takes on a whole new importance with these two new developments. Using facebook custom lists and retargetting, online stores can advertise on social media with data collected outside of it.
The opportunities for increased targeting and the management of your online advertising budget are immense.