Twitter Inauguration Day ratings are out — but please don't add them to TV, Sean Spicer

President Donald Trump and press secretary Sean Spicer have claimed that this year's Inauguration Day was the most-watched in history, which could be true depending on how you define "watched."

While Trump's crowd appeared much thinner than Obama's 2009 Inauguration, there's no denying that the viewership beyond the National Mall and on screens was quite yuge in part thanks to digital platforms.

Twitter, Trump's favorite social platform, presented the latest piece of evidence Tuesday. The live stream coverage of Inauguration Day on Twitter, presented by PBS NewsHour, reached 6,824,000 million unique viewers, the company announced.

That's quite a lot. But it's important to keep in mind that a view on Twitter is only three seconds, and with Twitter promoting the stream in users' timelines (rather than everyone opting in to watch), the engagement wasn't necessarily that impressive.

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Addition is easy, but not accurate

Twitter declined to provide average-minute audience (how many viewers there are in an average minute of the stream). It only reported that the stream had its highest number of concurrent viewership at 12:15 p.m. EST with 377,000 viewers.

Meanwhile, on the good ol' television, there were about 30.6 million total viewers, according to rating company Nielsen. That's far less than Obama's TV viewership of 37.7 million and Ronald Reagan's of 37.4 million.

If you add Twitter's and Nielsen's numbers together.... nope, let us stop you there.

First off, you'd still have less than Obama's 2009 Inauguration with that, but more importantly, this would be adding apples and oranges together. Nielsen's ratings are reflective of watch time. Twitter's and other digital platforms like CNN's reported 16.9 million viewers are not.

“I’m pretty sure that Reagan didn’t have YouTube, Facebook, or the internet,” Spicer, the press secretary, Dippin Dots hater and gum swallower, said Monday. “Let’s just take the Nielsen ratings, which are 31 million and add CNN, 16.9 million. That’s a little higher.”

Again, Sean, you cannot just add these numbers together. But, yes, you can thank digital for more access to Trump's Inauguration Day.

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But thanks to these confusing metrics and inability to connect users across television and digital, it is still undetermined how many people tuned in and if Trump drew the largest crowd. The size is not "unquestionable," as Spicer told reporters.

But good for Twitter

Inauguration Day wasn't a record-breaking day on television for Trump, but it was, at least, a good day for Twitter. The live-stream was Twitter's most-viewed stream to date, surpassing the 6.8 million unique viewers who watched BuzzFeed and Twitter’s live video on Election Night.

It's far more than Twitter pulled for its Thursday Night Football streams, which averaged about 3 million unique viewers per game, including the pre-show. It's important to consider that PBS NewsHour's coverage lasted six hours compared to a shorter football game.

PBS categorized the event as successful for the traditional TV network, as well.

"It was a smooth partnership," Nick Massella, director of audience engagement and communications at PBS NewsHour, wrote to Mashable in an email. "We are very pleased to see that the demographic breakdown of the audience allowed us to expose the NewsHour's quality journalism to Twitter's broad user base."

"We are looking for ways to work with Twitter again to explore how we can further create insightful live streaming news experiences that people want to see and share," he continued.