So what's Facebook good for?

Wasting time, yes I cannot agree with you more there. It's a time-suck the likes of a black hole on the internet. But understanding that in this case will help you better embrace what kind of content is appropriate and where best to make allegiances to better your Facebook clout. There are couple of key things to remember about Facebook.

Facebook is the Jr. High School of Social Networks. You need to be there and be active because there is such a time-synch there from users. But remember making your content too heavy can backfire on Facebook. Leave the intellectual banter to your blog, white papers and case-studies.
For most savvy companies using Facebook as a way to advertise, the presence of incredibly detailed profiles is what makes it such a fertile ground to advertise on. Users spend a tremendous amount of time, among many things "LIKE-ing" products, services, brands, entertainment and personal extensions of themselves such as liking "sleeping in" and drinking "merlot." This may all seem very silly to some but your customer is an intricate fabric of likes and dislikes, and the more you drill down to a granular 'target profile,' the more apt you will be to convert on your ROI.
Keep in mind that your Facebook "page" is a platform for timeliness within your vertical, thus creating greater awareness. The best thing your page can do is drive you to your website where you can begin the process or real conversion.
Remember that the most liked pages are things that connect people to entertainment, such as music, movies and television. †he least are things like local business and services. So the closer you can align your messaging with the popular culture of your demographic, the more apt they will be to connect with you.
Keep your content simple, entertaining and topical. And for God's sake have someone from the demographic you're trying to appeal to hired to connect with the user base. If you own a car that's more than 30k don't fool yourself, you DON'T know what Millenias are thinking.
Lastly, and possibly the most important, work with a social media professional or agency to construct a 'Social SOP.' You have an employee manual for your day-to-day business and you break down professional expectation in an employee description don't you? Social Media MUST have guidelines of usage, voice and directives. This will ensure that your brand speaks properly and consistently.

Do the math:

Both men and women on Facebook, on average have 130 friends. Start compounding the number exponentially should you message yourself correctly and people begin to "LIKE" your messaging. Because when someone likes you, this action is placed on their profile and dependent upon the trust level one has with that person, others often have the propensity to like things in return.