Last summer, Dan Oshinsky put a two-word subject line on a BuzzFeed newsletter about people who failed spectacularly at work: "You're Fired."

Lots of people opened that email. It also upset many of them. Readers — including Oshinsky's colleagues — replied, saying the newsletter made them think they'd been fired. The email's open rate, one of the ways news organizations measure the success of a newsletter, made it look like a hit. But feedback from the people who received it was starkly different.

"We want to delight our readers every single time they read a BuzzFeed newsletter — from the subject line to the content — and with an email like 'You're Fired,' we missed the mark," Oshinsky, who edits BuzzFeed's newsletters, said in an email to Poynter. "In 2014, it's been a point of emphasis for our team to try to be direct, honest, and funny with our subject lines."

BuzzFeed now de-emphasizes open rate as a "silver bullet" metric: It looks instead at click rate, the number of links readers click and how long each reader spends with the email. The newsletter team also monitors growth rates for every newsletter subscriber list and compares how many people are reading them on mobile and desktop platforms.

"They're all important numbers that help us get a better view of whether or not a newsletter is really working," Oshinsky said.

BuzzFeed doesn't disclose how many people get its newsletters or how many readers open them, but Oshinsky did say that so far in 2014 newsletter traffic to BuzzFeed is up 700 percent over 2013. And newsletters, he said, are now in the "top five or six" biggest drivers of traffic, behind sites including Facebook, Pinterest, Google and Twitter.

When Oshinsky joined the company in 2012, the site had just a handful of automated newsletters that he said "weren't very effective." He and BuzzFeed publisher Dao Nguyen decided they all should be written by a BuzzFeed staffer to make them feel more personal.

Now the publication has 14 newsletters, many of them aimed at specific segments of the company's audience. Among them: "BuzzFeed Daily," which serves up a list of links from the website, "BuzzReads," a weekly email with weekend longreads, and, of course, "This Week in Cats."

"Cats" debuted in 2014, as did "BuzzFeed Parents" and "Style," with another launch tentatively planned before year's end. In addition to Oshinsky, the company has added two associate editors, Adam Davis and Raymond Sultan.

Oshinsky said he tries to see BuzzFeed as a polite houseguest trying not to wear out its welcome.

“What’s exciting about email is, people invite you into this space and you get an opportunity to make a good first impression," Oshinsky said. "The downside is, if your emails are not good, you’re in a pretty important space and people kick you out.”