I've long been a critic of Twitter's (NYSE: TWTR) arbitrary 140-character limit that it imposes on tweets. The company has been wrestling with this idea for over a year, following CEO Jack Dorsey's return to the company he helped start. Investors appear to want the change, as shares tend to jump whenever the notion comes up periodically. Twitter reaffirmed its commitment to the limit in March (even after it removed the limit in direct messages), but then hedged its bets by excluding certain things like @ mentions, media, and links from the limit in May. This last move implies that 140 characters really isn't sufficient.