Yikes, the "What if I told you.../What if I tell you.../How would you feel..." ones are terrible. Those would be an automatic delete for me just because they sound spammy right off the bat.

I agree, but keep in mind the real question isn't "does this work for you?" but "does it work for a large enough number of people to be useful?"

See also: Buzzfeed

I find their style of headline verges on insulting my intelligence, but they've gone to great lengths to statistically prove I'm not the average person.

Every time I hear "What if I told you...," I can't help thinking of that pathetic old-timey producer character on Entourage who was always asking, "What if I told you [XYZ]? Is that something you might be interested in?"

Now, psychologically speaking, "What if I told you [I could solve your problem]" is the correct sort or narrative structure to use in many pitches. But rarely do you want to use that exact phrasing. It can read as cheesy.

"9) “I’ve been following your blog and social media updates for quite a sometime and there is one thing that would be nice to discuss with you.”

Yes, here, take all my money, you've bested me with your sales copywriting and social engineering.

All of these example are an easy insta-kill for me, especially if the placeholders like "problem" are filled generically. What bothers me more are personalized mails like this one:

Hi <my first name>,

Just curious what your impression of <product> is so far. Are there any technical issues you've come across which could be blocking you? Do you/your team have a particular project in mind, or are you just trying to keep up with the latest in <our technology>?

-<sender first name>

I have to think twice, if this is really auto/mass mail. This probably converts much better than the article's lines, but is also a different case.

I get dozens of emails like these every day and they drive me nuts. I wish people would get straight to the point rather than waste my time padding out the top of their emails with disingenuous small talk.

This a million times for sales calls. I like to be polite if they get through. They tend to mince about the point with niceties or building up to what they are selling. I'll even say "I can hear this is a sales pitch, please get to the point' They rarely do and then close the call. If they got to the point in 15-20 seconds they have the best chance of me deciding if it's interesting or not.

I'd recommend running them by someone for whom English is a first language before using any of these.

My personal favorite is "Holy shit!" followed by

"Holy shit I can't believe you opened this!"

Cold e-mail? That's just spam. Stop mailing me just because I have a (private!) website.

tl;dr: Start off with personal info

Most of these I'd still trash anyway, but I would at least take a second since they differentiated themselves from spam

Summary -- There are two themes here: appealing to someone's (1) vanity or (2) pain.

With the title "Cold Email Opening Lines," I was half-expecting things like "I don't care if you live or die," or "Millennia from now, when the sun engulfs the earth, nothing we do now will have mattered. Buy my service."

I might actually read that last one!

But, frankly, they lost me at the title of the post. Anyone who calls me a 'lead' is someone I probably have no interest in talking to.

We changed it from the baity original earlier, but it seems we overcorrected, so we'll add back the phrase "sales leads".