"I think there is so much potential in Twitter that we haven't yet unveiled," said Twitter (NYSE:TWTR) co-founder and board member Evan Williams in a CNBC interview last October. Williams said he expected bold and innovative changes to come in a matter of "months," and that he was confident the company's returning CEO and co-founder Jack Dorsey was ready to deliver on these expectations.

Twtr Hq

Twitter headquarters. Image source: Twitter.

Nearly five months later, Twitter stock is down about 48% and the company's pace of execution in product innovation continues to disappoint. And Twitter's Tuesday-announced change in how it counts characters puts the spotlight on management's unimpressive pace of execution.

Too small, too slow

A change to how Twitter counts characters for its tweets was much anticipated and long awaited. Rumors had suggested the company could allow as many as 10,000 characters in a tweet -- a move that would fundamentally change the way the social network is used.

And even Twitter executives seemed to suggest the change would be big. When asked about whether the company would drop the 140-character limit at the Code/Mobile conference last October, former Twitter product lead Kevin Weil, who recently left Twitter to work at Facebook (NASDAQ:FB) as head of product for Instagram, told Re/code that the company wasn't "shy about changing something that's at the core of Twitter."

Furthermore, in January Twitter CEO Jack Dorsey tweeted screenshots of text including over 1,000 characters, seeming to explicitly hint at a bigger change.

But it looks like Twitter wants users interested in sharing longer tweets to stick to ugly screenshots of text which isn't even searchable or able to be highlighted with a cursor. Twitter stock slid about 2.5% on Tuesday when the unveiled change fell short of expectations.

The change? In a nutshell, usernames used for replying and media attachments will no longer count toward the 140-character count, and replies can now be broadcast to all of a user's followers. Oh, and users can now retweet and quote-tweet themselves. Essentially, users have a few more characters at their disposal.

Twitter's timeline for the rollout of this product feature further emphasizes the company's slow pace of execution.

"These updates will be available over the coming months," Twitter said. The blog post asserted the updates "have a significant impact on Tweets," so Twitter wants to give developers and partners time to make any needed updates.

This change is not only just incremental -- but it's arguably necessary. As users increasingly include more media, hashtags, and tagged users in their tweets, more room is needed to say the same things.

Bigger changes required

Twitter's slow execution stands out when looking at how much Facebook has changed in recent years. Facebook's big changes included separating Facebook Messenger into its own product, introducing ways to transfer money within Messenger, completely overhauling its "Like" button to include a range of reactions, and rolling out live video-streaming tools to all of its users. While Twitter has also made changes to its product during this time, they aren't nearly as fundamental as Facebook's. To be fair, Facebook is a tech juggernaut with far more resources at its disposal. Still, it's difficult to overlook the huge difference in the two companies' paces of improving their services.

Twitter investors are likely disappointed in Tuesday's news, simply because this doesn't look like the innovative change and accelerated pace of execution needed to help the company transform itself into a service with more mass-market appeal. Sure, 10,000 characters may not be the right solution. But a small change like this isn't likely to move the needle enough to make a big difference in the trajectory of Twitter's future.

Daniel Sparks has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Facebook and Twitter. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.