It might as well be 2006 for all the cash social networks aren't raking in. During its recent earnings call, Google complained that ads on social sites like MySpace and YouTube weren't meeting expectations. The WSJ reports Microsoft is losing money on its Facebook deal. Meanwhile, analytics firm eMarkerter expects ad spending on social networks to increase 70 percent in 2008, but that's an increase to only $1.56 billion. So who's to blame? One Google exec says it's those old-fashioned ad agencies.