If I were strongly bullish on FB and wanted to play the earnings I would sell the weekly (expire in 11 days) 54 put (4$) buy the 54.5 call (4$) as an syn long. unlimited risk to the downside so "just" in case I was wrong I'd buy the DEC 13 (60 days) 46 put for under $2.
If FB does tank I can roll my short put each week to reduce the potential loss.