Unlike some other channels, both broadcast and cable, FX usually takes its time deciding whether to renew its series. "Sons of Anarchy" season 3 wasn't ordered until fairly late into season 2, even though the outlaw biker drama had already become the biggest hit in FX history.

Five episodes into season 3, though, it's so clear that "Sons" is and will continue to be a hit that FX decided not to wait in announcing their order for a season 4, to air next year.

This year, "Sons" is the highest-rated scripted show on cable in the advertiser-coveted 18-49 demographic. Each epsiode averages 4.9 million total viewers and 3.4 million viewers in the demo. Factoring in multiple plays across the week, those numbers go up to 8.6 million overall and 5.9 million in the demo.

“Sons of Anarchy is the most popular show FX has ever had, and the #1 series in basic cable for our key demographic.  It is also one of the best, most original series on television,” FX presdient John Landgraf said in a statement. “FX is grateful to Kurt Sutter and his team of writers, actors, directors and crew for working so hard to make a show that achieves both those levels of success.   We congratulate them and look forward to season four.”

You can read my "Sons of Anarchy" season 3 reviews here.

Alan Sepinwall has been reviewing television since the mid-'90s, first for Tony Soprano's hometown paper, The Star-Ledger, and now for HitFix. His new book, "The Revolution Was Televised," about the last 15 years of TV drama, is for sale at Amazon. He can be reached at sepinwall@hitfix.com