By now you've probably heard that Monday's ninth-season premiere of the CBS sitcom "Two and a Half Men" scored the series' best-ever ratings , pulling in 28.7 million viewers. The show, of course, has been reformulated following the very public meltdown and exit of its longtime star Charlie Sheen; on this week's episode, Sheen's character was killed off (and mercilessly ridiculed at his funeral), and Sheen's replacement, Ashton "That '70s Show" Kutcher, made his debut. I watched the show after the fact -- the full season-premiere episode is available (for now) at CBS.com's "Two and a Half Men" page -- so I didn't engage in the real-time "social TV" conversation about it. (My day-later reaction: It was great to see Kelso again, but I miss Jackie, Fez, Eric, Donna and Hyde. And especially Red and Kitty.)

But given that Ashton Kutcher is deeply associated with social media -- he was famously the first Twitter user to rack up 1 million followers -- it seemed likely that his addition to the show dramatically amplified its "social TV" footprint: the extent to which people talk about it on social media. As it happens, the team at Ad Age 's editorial partner Bluefin Labs, a Cambridge-Mass.-based social-media analysis company that specializes in social TV, told me that they'd collected social-media responses to last year's "Two and a Half Men" season premiere (when Charlie Sheen was still on the show) and this year's, as well as all the airings in between. You know what that means: charticle time!

Some notes about the chart below:

• The bars shows the volume of social-media comments (primarily on Twitter and in public Facebook updates), as collected by Bluefin Labs, for prime-time episodes of "Two and a Half Men" airing on CBS; reruns of "Men" also air on FX, but we excluded those episodes in this analysis. Also, the chart shows social-media commentary specifically related to airings of "Men" -- not for Charlie Sheen in general, which is important because of course Sheen became a social-media sensation (remember "#winning"?) during his prolonged exit from the show.
• Bluefin tells me that throughout the course of last season, "Men" only garnered about 1,000 social-media comments per episode, on average.
• As you'd expect, there was a clear spike in social-media commentary in late February and early March. (Charlie Sheen checked into rehab on Feb. 23, temporarily halting production on "Men.") The off-air controversy more than tripled the number of social-media comments about episodes of "Men."
• The debut of Ashton Kutcher on "Men" had a truly massive effect on the show's social-TV profile. Monday's season premiere garnered more than 92,000 social media comments, as recorded by Bluefin, whereas the high-water mark for the final Sheen episodes of "Men" was just over 5,000 (for the Sept. 12 airing of a rerun). See that double-slash breaking up the far-right bar in our bar chart below? We had to break scale because otherwise you'd have to scroll forever to compare the social buzz from the Sheen era to the stratospheric social buzz at the dawn of the Kutcher era.
• I asked Bluefin's Tom Thai what he thought about the Kutcher social-TV effect. "Kutcher and his 7.7 million Twitter followers played a big role, for sure," Tom told me. "But they weren't the only force. Over the last 12 months, social-TV activity in general has really taken off. Audiences are participating in what we call 'virtual co-viewing experiences' -- like tweeting while watching TV -- more than ever." In other words, Ashton Kutcher is the right star at the right time to bring "Two and a Half Men" into the social-TV age. That said, it's unlikely that Kutcher will be able to drive such stratospheric levels of social chatter about "Men" week after week; social buzz about his debut on the show, of course, got a huge boost from both armchair critics (e.g., those who wanted to weigh in on whether Kutcher measured up to Sheen) and from the mainstream media that treated Kutcher's arrival as a pop-cultural event.
• It's worth noting that Charlie Sheen (@charliesheen) is closing in on 4.9 million Twitter followers -- but he only debuted on Twitter on March 1 of this year during the peak of his media notoriety. Kutcher (@aplusk) first tweeted on Jan. 16, 2009.
• One final note: We don't usually pay much attention to sentiment analysis -- in which complex algorithms parse the positive, negative or neutral sentiment of social-media messages -- in the social-TV coverage here at Ad Age . My feeling is that it doesn't necessarily tell you much because sentiment about popular shows generally skews positive (of course), and seemingly negative tweets might actually be stealthily positive (for instance, when fans tweet about a character they love to hate). Basically, Bluefin sentiment-analysis data shows that fans really liked "Two and a Half Men" during the Sheen era and they really like it (so far) in the Kutcher era. But I was curious about one thing: Did Sheen's Feb./March meltdown affect how viewers related to the show? Yep -- at least in the immediate aftermath. Bluefin tells me that negative sentiment in social-media comments about "Two and a Half Men" rose 22 % for the Feb. 28 episode and 26% for the March 7 episode.

Stay tuned to AdAge.com for more data from Bluefin Labs.

For more about Bluefin, visit its website.

Simon Dumenco is the "Media Guy" media columnist for Advertising Age. Follow him on Twitter @simondumenco.