Shane Goldmacher for Politico:

Donald Trump has plastered Facebook with millions of dollars worth of ads in recent months, an all-out effort to lure new donors and supporters. But his campaign filings from August, September and October tell a different story: $0 spent on Facebook.

The vast discrepancy is possible because Trump has leveraged an increasingly popular loophole for politicians seeking to outmaneuver an outmoded campaign-finance system: routing their spending through consulting firms to obscure the ultimate destination of their dollars — keeping the public in the dark about facts as basic as who they’re paying and how much they’re paying them.