How much does spam cost? It’s hard to quantify in terms of bandwidth, time and effort blocking it, and general nuisance. But here’s a figure to mull over: $873m.

That’s how much Facebook has been awarded in damages against a spammer in a US court for sending unsolicited messages on the Facebook network. And if it sounds trivial in this era of multi-billion dollar bailouts, it’s a lot more than Facebook’s expected revenues for 2008 – more than double, in fact.