Does absence make the heart grow fonder? When it comes to TV, not always.

We here at Ad Age were curious about what happens when a show goes on short or extended hiatus, because it increasingly seems that there's no rhyme or reason to when you can expect your favorite show to shift from fresh episodes to a string of reruns (or even get taken off the air for a while). And so we worked with our editorial partner Bluefin Labs, the Cambridge-Mass.-based social-TV analytics company, to take a look at what happens to social buzz and ratings when shows go into hibernation and then return. Scroll down for some context.

• Fox's "Glee" returned with a fresh episode, titled "Big Brother," this past Tuesday after 49 days on hiatus. Viewer reaction was just sort of "meh" -- with a so-so 13% boost in social buzz over the last fresh episode and soft ratings (soft for "Glee" anyway). Nielsen says "Big Brother" pulled in 6.76 million viewers, compared with 7.46 million for the previous new episode in February. To put that in context, "Glee" has exceeded 9 million viewers a couple of times this season.
• In the case of shows that have intensely buzzworthy storylines -- plots that seem basically tailor-made to get fans talking -- a hiatus can actually be great for business. For instance, ABC Family's "Pretty Little Liars" -- which went on a 75-day hiatus in October, resuming its second season only in January -- had a 983% boost in social-media buzz and added nearly 900,000 viewers. Nielsen reported a bump in viewership for its January-return episode of 3.34 million vs. 2.47 million for its last pre-hiatus episode.
• If you scan the rest of our chart, the takeaway seems pretty simple: Sitcoms -- which seldom have plots that pivot off cliffhanger-y storylines -- tend to suffer (or stay basically flat, as in the case of "How I Met Your Mother ") on when they go away and come back, while dramas tend to gain.

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.