Why did that all-important, life-changing tweet you feverishly posted lose steam after just a few minutes? Odds are, it’s because you’re just not influential enough.

Klout, the startup that measures a social media users digital influence, analyzed a week’s worth of retweet data and researched the correlation between the life of tweets — as determined by the spread of retweets — and Klout scores. The startup specifically looked at the half-life of tweets (pictured below). The half-life of a tweet is the point when half of all retweets happened before that point and half occurred afterward.

As expected, it turns out really high Klout scores do equate to longer-lasting tweets. The startup determined that tweets originating from a Twitterer with a Klout score of 75 or higher last hours longer on the information network than tweets from those with a score that falls below that threshold.

“Influencers with a Klout Score above 75 have a half-life up to 70 times longer than those with a score between 30 and 70,” explained Andras Benke, the researcher behind the Klout study.

“The top echelon of users have content that not only gets spread more but actually lasts longer,” Klout marketing manager Megan Berry said when we pressed for more information.

According to the data, if you have a Klout score between 75 and 80, the half-life of your tweets is 2 hours and 45 minutes. The half-life of a tweet jumps to 5 hours and 15 minutes for users with Klout scores between 80 and 85. That’s not too shabby when compared against the half-life of tweets for those with scores between 40 and 70. This sad group of folks, which includes yours truly, will find that their tweets reach the half-life point after just five minutes. So our tweets do get dispersed via retweets, as the second chart ilustrates, but they die off rather quickly.

VentureBeat pinged the company to find out just how many users fall into each of the half-life buckets. Klout stayed mum on the specifics, but did share that the average score is 20, and added that a score of 50 or more puts the Klout user in the 95th percentile of users.

Of course, Klout’s retweet analysis is only valid if you buy into the company’s methodology for assessing social media influence. And after the startup radically reworked its formula a week ago, who could blame you for second-guessing it?

[Kenneth Young for Snapfocus/Flickr]