There’s something to be said about keeping it simple, and that may be the keystone to the house of Twitter’s long-term sustainability.

Rory Sutherland, the influential advertiser that helped mold Microsoft into the global tech giant it is today, expects that Twitter will not only outlast Facebook but also grow to become more valuable. Talking to The Telegraph yesterday about the long-term shelf life of the two social media websites, Sutherland opined that Facebook was more vulnerable to competitors than Twitter.

“I can see Facebook being superseded more easily than Twitter being superseded,” he said. “As a forum for outbursts, Twitter’s [character] limit, its haiku element is very appealing. I wouldn’t bet against it being more valuable [than Facebook] in the long term.”

Sutherland added that Twitter has an untapped financial potential that many people have yet to recognize.

Although Twitter may end up being more valuable in the long run, that hasn’t prompted any hasty decisions from the site’s leadership. Earlier this year, after Facebook’s much-discussed decision to go public, Twitter CEO Dick Costolo brushed away speculation that the micro-blogging site would be following suit anytime soon.

“We don’t want to be public until we have very predictable quarterly earnings growth,” Costolo said in staff email. “We’re not ready to be a public company for a couple years.”

Costolo has cautioned before that he doesn’t want to rush Twitter into going public. In February, at All Things D’s D: Dive Into Media conference, Costolo said that he wants Twitter to be a “decades-long, lasting business.”

You think Twitter’s got the legs to not only outlast Facebook, but span into the next couple of decades? Why or why not? Using more than 140-characters, share your reactions below.