From your comments, I'm assuming that you believe: 1) Tasers aren't particularly effective, and 2) You're supposed to be knocked unconcious. Neither is true of Tasers.

I have yet to see any credible refutation of the manufacturer's claim of 94% stopping ability in the field, so that's as effective as any handgun. Unlike "stun guns," Tasers don't work by generating pain; they cause your muscles to contract involuntarily so you can't control them yourself. That hurts, but the pain is a byproduct of how the Taser works.

You're rendered helpless while being shocked, but typically don't black out unless you fall and hit your head. You typically recover very quickly after the shock is stopped. The Taser model discussed in the article, the C2, automatically discharges for 30 seconds after firing. This gives the user the time to drop the Taser and then get the heck out of there while their attacker is incapacitated on the ground. That's how it's meant to be used in self-defense situations. Unlike a gun, where if you're put down, you're generally going to stay down until the police/paramedics show up, someone who is Taser'd can get back in the fight when the shock is ended so you need to get away while you can.