Twitter’s 140-character limit makes it hard to have a thoughtful discussion. Brevity is great, but not for everything.

I was having one of these discussions with Rob Frankel—@brandingexpert—about whether Burger King got any value out of its “Whopper Sacrifice” campaign. This wasn’t a disagreement, just an interesting conversation. Conducting the exchange over Twitter lacked something, though. Hence, this post.

The conversation-starter was Dave Fleet‘s live tweet from something called FacebookCamp, held February 24 in Toronto. Dave reported on a speaker who asserted that pushing the campaign’s message through mainstream media was more effective than tapping into social media, despite the campaign’s focus on a social network. It was the originality of the concept that captured mainstream media’s attention and produced the coverage that made it common knowledge.

Early in the discussion, Rob noted that the campaign may have gotten widespread coverage, but its notoriety never translated into dollars.

I’m not surprised. Although the campaign apparently led some 23,000 people to dump 10 Facebook friends (which, in case you missed it, would earn you a free Whoper), that’s hardly a significant uptake for a national campaign. And while you have to wonder who devalues friendship to the point that they’d dismiss 10 friends for a cheeseburger or if those 23,000 had enough friends-who-really-weren’t-friends that they could easily spare them, that’s beside the point. The point, as Rob notes, is that the campaign didn’t generate sales, which is the goal of advertising (unlike the goal of public relations, which is to build and maintain relationships). I also recall hearing somebody on one podcast or another argue that the idea couldn’t be duplicated; if enough companies adopted a similar approach, you’d eventually end up with no Facebook friends at all.

But I thought the campaign might still have produced some value for Burger King if it helped maintain BK’s reputation as the edgy burger franchise. Before it abruptly changed the tone of its advertising, BK was stuck in the same rut as all the other fast-food chains: competing with McDonald’s image as a wholesome, family-and-community-oriented, all-American icon.

Tired of the rut and with a new CMO in place, BK decided to shake things up and concede the motherhood-and-apple-pie ground to McDonald’s. Instead, they embarked on a series of irreverent campaigns, from TV episodes with the King to the Web-based Subservient Chicken. The chicken went viral and attracted millions of visits, but I’m not sure that was ever directly linked to sales of burgers and fries.

My question is, does it have to be? Rob thinks so:

But here’s what I’m wondering: Has BK has been increasing market share gradually over the life of the campaign? Rather than impact sales directly with each ad, each web page, each campaign, has Burger King been gradually attracting customers at a slow and steady clip?

If so, then you can make the argument that the advertising direction as a whole is paying off. The immediate results of each little piece don’t matter; the sum of all the pieces is what counts.

Well, yeah, sounds good. Based on some quick online research, in October 2008, Burger King was was ranked second to McDonald’s with 15% of the market and growth on the books. But nine years ago, BK was reeling from a loss of market share…from 20.2% in 1998 to 18.8% in 2000.

The fact that Burger King’s market share is nearly 4% worst today than in 2000, it would be easy to conclude that the company’s irreverent advertising and marketing efforts haven’t paid off. There’s no evidence to suggest that other factors aren’t at play, from greater competition from more quarters to the quality and originality of the menu to the impact of staying open late. In fact, I couldn’t prove that the King, the chicken, and the rest of the bizarre BK cast haven’t kept the chain’s market share from diving even deeper.

These were the thoughts I was trying to convey in 140 characters. I just couldn’t do it. And I’m left wondering how much companies values the long-term affinity for a brand that attributable to advertising and marketing efforts even if the individual pieces don’t produce immediate sales.

Thoughts?