Twitter (NYSE:TWTR) finally started to loosen post size restrictions on Tuesday night. The social media juggernaut announced that it will double the size of the characters allowed on tweets in most languages on some accounts. 

Raising the ceiling on platform posts from 140 to 280 characters is a welcome if not long overdue move, but let's not assume that this is what was holding back growth at Twitter. We're talking about a dot-com legend where revenue declined in its latest quarter. Giving its users more posting flexibility is nice, but it's not an elixir. In fact, it may even be counterproductive to both growth and monetization. Twitter faces several challenges these days, and Tuesday's move -- while being largely applauded -- won't solve it's problems. In fact, it may actually make things worse.

A Twitter blog post showing longer posts with the 280-character cap on tweets.

Image source: Twitter.

Flipping the switch

There is naturally a lot of buzz surrounding Twitter's big move, but before we begin to address the financial implications, let's delve into the problem with how the rollout is being carried out. Just some users are getting a taste of the new feature, and for now that seems limited to high-profile, verified accounts. The vast majority of Twitter's base is still pecking away with a 140-character cap, and that may not come off well when they bump against that ceiling to see if they are among the chosen ones on Wednesday. One can argue that Twitter is right in limiting its audience for a feature that it may repeal in the coming weeks, but would Twitter really take something away that it just unlocked for its more prolific posters? You can't stick a genie back in the bottle.

Now let's talk about what the move will mean for Twitter's bottom line. In the best-case scenario, this means nothing. Instagram and Snapchat are social platforms growing a lot faster than Twitter and possibly at its own expense, and they're more visual than textual. Word counts just aren't as relevant now that even Twitter is a haven of GIFs and other eye candy. 

In the worst-case scenario, this move winds up tripping Twitter. Even the blog post announcing the move plays up that brevity is the platform's calling card. Giving some and eventually all users the ability to post messages twice as long will mean folks having to scroll twice as long to see as many messages as before. Will that help or hurt engagement? 

Money talks

What about monetization? Revenue slipped 5% in Twitter's latest quarter despite modest but positive user growth and engagement trends -- monthly active users were flat sequentially but up 5% over the past year, with daily active users up a hearty 12% over the past year -- because the platform is having a hard time milking more ad revenue out of its accounts. Longer tweets translate into fewer posts on a screen and likely fewer promotional opportunities. Advertisers that have stayed away since they can't control the nature of someone's 140-character post also won't feel any better tethering their brands to the platform when polarizing Twitter users have twice as many chances to offend. 

Twitter's giving users what they wanted years ago, and it may not align with what marketers and shareholders want right now. The pitfalls are there, and you'll need a lot more than 280 characters to spell them all out.

Rick Munarriz owns shares of Twitter. The Motley Fool owns shares of and recommends Twitter. The Motley Fool has a disclosure policy.