Doesn't Work against Spam

Ok, I don’t mean to be a party-pooper but there was a time this plugin used to work because I was using it on well over 10-15 sites, but within the last 4-5 sites I’ve used this on, it doesn’t work at all.
I mean, yeah it stops invalid human submissions but if anything I am seeing an increase in spam comments compared to the time when I didn’t have this plugin installed.

What I don’t get is why are so many people so happy with it. My guess, because their sites are not generating enough traffic organically to be targeted.

Either way, I would love nothing more to rate it higher if the authors can figure out why it’s not blocking anything anymore.