Twitter was originally built as a text messaging service. You send a message to 40404 and Twitter would automatically publish it on their website. Your tweets would also be sent to all of your followers as a text message and you could use certain shortcuts — DM, RT, track, follow — to perform various functions.
This is where Twitter’s character limit came from. The SMS protocol only allows messages that are 160-characters long. 140-characters gave the company some wiggle room to include a small amount of metadata (like usernames) alongside the full text of the tweet.
But native applications have become the primary interaction point for Twitter users. The company doesn’t have to rely on SMS anymore and can ditch the old character count baggage. I’m not positive that 280-characters is the right number, but I’m the type that would rather err on the side of caution and try something smaller first. Something around 200 feels better to me.
But I’m glad they’re doing something to freshen up the service. I just hope that doubling the length of tweets doesn’t negatively impact the usefulness of my timeline. Brevity is Twitter’s best feature. And I hope that isn’t going away when the 280-character switch is flipped on for all users.