Conan O’Brien returned to the small screen last night. While we’ll have to wait for the ratings, one thing is certain: Conan’s debut on TBS is not only a big deal for TBS, it’s a big deal for cable television at large.

Not surprisingly, the run up to Conan’s television resurrection has been highly-anticipated, and supported with a hefty dose of promotion.

When it came to promoting the premiere of Conan, TBS didn’t forget about Twitter. The popular service is not only one of the most popular social media hubs, it has played a key role in Conan’s career and stardom post-NBC.

At the top of Twitter’s Trending Topics list yesterday: #conanreturns. Beside it: the ‘Promoted‘ graphic denoting that this hashtag was a Promoted Trend. Ostensibly, like other promoted trends, TBS paid for this. But did it have to? Below #conanreturns floated four other CoCo-related Trending Topics: #teamcoco, ‘Watching Conan‘, Rogen and Seth Rogan (Rogan was a guest on the premiere). In total, four of the ten Trending Topics on Twitter had to do with Conan. Only one was paid for.

The question this raises: did TBS waste money buying its Promoted Trend?

It’s a difficult question to answer. On one hand, it may not have been advisable for TBS to count on organic buzz, recognizing that organic buzz is often driven in large part by sparks from paid promotion. On the other hand, the fact that three other Conan Trending Topics surfaced without any apparent cost does seem to highlight the fact that if you have something that’s buzzworthy, there’s a good chance buzz will follow — no payment necessary.

For TBS, questioning the wisdom of spending money on a Promoted Trend is an entirely academic exercise. The network has placed a huge bet on Conan and was obviously going to back it up with an investment in promotion. It’s unlikely that the Promoted Trend was a significant part of its overall spend.

But the organic, unpaid buzz Coco generated does raise practical questions for marketers considering a Promoted Trend. The biggest question: if our message can’t achieve buzz on its own, how much worthwhile buzz will a Promoted Trend generate? Marketers should consider that while there’s room for paid promotion in social media, you can’t really buy the virality that you’d like to. A Promoted Trend might purchase some exposure for a price, but genuine, grassroots buzz is at the same time both priceless and free.

Photo credit: Repoort via Flickr.