Depends on the cold figures I suppose. If you're willing to waste (and sometimes it truly is waste) time and money on a few hundred failures for one success, then maybe it is.
The cynic in me though thinks that the one success probably would have come looking for the help voluntarily.
Sigh - I accept I cannot really comment here. My view is massively skewed, because of course I meet, regularly and consistently, those people who have had all the help, failed to cease their habit, and reoffended. There's a part of me that thinks that when you're looking at a habitual offender with over 250 convictions, perhaps it's time to admit defeat and simply protect society rather than continue efforts for that single individual (and yes, I quote from experience there).
Like I say though, perhaps I'm not best placed to comment - perhaps there's the bloke out here with 249 convictions that's turned his life around after having drug treatment forced upon him yet again!