The VOAL formula ends up looking like this:

L (Total Likes): The total number of audience members connected to your social media account. On Facebook, these are Likes of your page, and on Twitter, these are followers.

UpM (Unlikes-per-Month): The average number of fans who "unlike" your social network account each month. On Facebook, this is an "unlike," and on Twitter, this is an "unfollow."

LpD (Links-per-Day): The average number of times you're posting links, and potentially converting links driven from your social media account. On Facebook, this is the number of posts you're making, per day, that lead to a page on your website. On Twitter, this is the number of times, per day, you're Tweeting these kinds of links.

C (Average Clicks): The average number of clicks on the links to your site you're posting on your social media accounts.

CR (Conversion Rate): The average conversion rate of your website, from visit to sale or visit to lead. This can be an overall average, but for increased accuracy, use the conversion rate measured from traffic coming from the social network you're calculating.

ACV (Average Conversion Value): The average value of each "conversion." In this context, a "conversion" is the action you've used to measure CR for. It could be average sale price or average lead value. For increased accuracy, use the average conversion value of traffic coming from the specific social network.

I'm not quite sure that having the VOAL formula is better than nothing.

Social media is changing so much that it's unclear that links-per-day, average clicks, conversion rates, and average conversion value are actually stable numbers.

 I think if you could solve using the voal formula to figure out how much you need to spend to reach some goal, it might be useful. 

Useful for a short-term goal but longer term all bets are off.

Mark Cuban says Facebook wants to charge him $3000 to reach a million of his fans.

That's today. No telling what they'll charge tomorrow.

 Lol.  Well, for him $3k is peanuts, so might be worth a flyer, but secondly, he can't reach a million of his fans by himself?  They are going to need a little more demographic breakdowns on that one. 

$3k for every post ends up being a lot of money, year after year.

He's right to be pushing back now. What's to keep it from going to $10k or $50k a post?