Failed Experiment

Over the weekend I decided to try an experiment to see if I could increase the number of comments I get on posts.
Typing in the letters that appear in the word verification is, apparently, the hardest thing ever - or, at least, more trouble than it's worth just to be able to comment on something I wrote (or drew) - so I actually turned off the word verification requirement.
The experiment was to see if this would increase the number of spam comments I got by an unacceptable amount. If, after some time with the word verification turned off, all I saw was the odd bit of spam here and there, I'd leave it off.
...
I was almost immediately inundated by spam comments.
Oddly enough, most of them were on a single post from over four years ago. I realize that automated spambots make leaving comment spam effortless, with little or no cost, making even the most infrequent success (i.e. someone actually clicking on the link(s) included in the comment) disproportionately profitable, but spamming a 4 year-old post on a blog with as little traffic as this one? Yeah, I can't see that ever paying off.
In any case, Blogger has a built-in system for detecting comment spam that seems to work pretty well, so none of the spam comments actually showed up on the blog, as they were awaiting my approval. So Threshold itself wasn't actually getting spammed.
I, however, was, since I receive an e-mail notification whenever someone leaves a comment.
There isn't really any way that I could filter my e-mail to differentiate between legitimate comments and spam comments, and I like being notified when someone leaves a comment - with the word verification, turned on 99% of the time they're legitimate, non-spam comments - so the only option that was available to me if I was going to leave word verification off and not get my inbox spammed - turning off e-mail notifications - didn't appeal to me.
Now, if I regularly got dozens of (real) comments a day, I'd probably turn the notifications off anyway, in which case I could go ahead and turn off word verification.
But given the small number of comments I get, right now, seeing a notification in my inbox is kind of a treat. Would the amount of spam I get be offset by real comments left by real people who have simply been waiting for commenting to be a little simpler if I left word verification off, and would the total volume make the notifications superfluous?
Given the amount of traffic this blog gets, I doubt it.
So unless there are masses of people who are willing to face that onerous word verification just one time in order to leave me a comment telling me that they would comment regularly if only they didn't have to go through the backbreaking labor involed in typing in an extra five characters to leave a comment, it seems that word verification is here to say, and the word verification-free system was a failed experiment.