Care2's nonprofit online marketing blog, frogloop, recently released a dual post on social networking worthy of a read from even the most staunch social networking gurus. Both the ROI Calculator and The Long, Long Tail of Facebook Causes articles will help you determine whether marketing on social networking makes sense for you.

The first one, an ROI Calculator, will help you calculate an estimate of cost and return on investment for the recruitment and fundraising efforts of your staff in social networking sites like Facebook or MySpace. It works sort of like an online mortgage calculator.

Just enter the starting assumptions like cost per hour of staff/volunteers, social network "friends" recruited per week, and the average response rate for outreach or advocacy mailings, and the tool calculates results automatically. This is a fantastic way to help you determine whether or not developing a presence on social networking sites is worth your hard earned dollars and precious time.

Secondly, The Long, Long Tail of Facebook Causes, provides the first comprehensive breakdown of the Causes application's performance. The study found that if you disregard all of the "Causes" that have $0 donated, you can expect about $1.24 per supporter. Perhaps more relevant, though, are the median and the mode, which you can click-through to find out.

The post finishes off with tips for promoting a Cause on Facebook (like advertising your Cause on your website) and points out some flaws in the Causes application (like splitting up your supporters) that either the developers or some other ambitious entrepreneurs should resolve.

Between being called a "must read" by Beth Kanter, featured on the DMA blog, showcased by the Beaconfire Wire, and being named "Download of the Week" by MyRagan, both posts are certainly worthy of a read before embarking on any social networking campaign.