It appears as if Twitter was unable to reach agreements with UK carriers to keep costs of its SMS tweets down. While users will still be able to send updates to a phone number, they will no longer be able to receive them on phones.

With Twitter's text option, a user's blog update could turn into dozens of text messages depending on who is following that particular user, which the Twitterer was not paying any additional fee for.

"That's because we've been footing the bill," co-founder Biz Stone wrote yesterday in a post to the company blog. "When we launched our free SMS service to the world, we set the clock ticking. As the service grew in popularity, so too would the price."

Stone said that even with limits of 250 received messages per week, it will cost the company $1,000 per month per user to continue sending out texts. Simply put, for any large service, it can become prohibitively expensive to offer some type of texting option.

Twitter's change, announced today, does not affect its cell phone update services in the US, Canada, and India, where the company was able to establish relationships with carriers in order to keep SMS services sustainable. It does affect those elsewhere and not necessarily in the UK who may have been using their phones to receive text updates.

The service simply couldn't continue to bear the burden of each tweet's cascade effect. Twitter said that it would continue to negotiate with carriers in other portions of the Americas, as well as elsewhere across Europe, Asia, China, and Australia, to allow for receipt of tweets via text.

Users of the service are not happy with the sudden move, and expressed their displeasure through posts to its Web site.

"Really annoying that DMs won't arrive by SMS anymore," Taptu community leader Vero Pepperrell wrote. "Twitter canceling its text messages in the UK is a massive blow for journalists who could receive updates on the move," UK-based tech journalist Paul Bradshaw quipped.

In a attempt to quell some displeasure, the company said in the near future that it will be debuting new SMS numbers throughout Europe. However, this would just make it cheaper for users to text in their updates, rather than make a long-distance call to the UK.

Twitter has recommended that users send and read updates over its mobile Web portal, as well as use Cellity for Java-enabled phones, TwitterBerry for BlackBerrys, or Twitterific for the Apple iPhone.