It may be hard to wrap your head around a device that exists solely to Twitter, but that does not negate its existence.

Starting today, Amazon is selling the TweetPeek. For the low price of $199, you can tweet for life. You may be wondering why you would shell out $200 for a feature that can be easily had on most mobile phones already. Well, that’s a good question.

Dedicated devices have the benefit of doing one thing, really well. The Flip camera for instance focuses on video for a low price point (Yahoo calls it “The world’s simplest video camera.” Peek Inc. has a similar model. The original Peek is a mobile device dedicated to email. It may not be better than other services, but it is cheaper than many monthly mobile phone plans. And that is part of the thinking here.

Twitter approached Peek in June and the TwitterPeek is being revealed only four months later. It comes in charcoal gray and Twitter’s signature blue.

But it is cheaper than many smartphones. It is currenlty selling on Amazon. $199 buys you “lifetime” access to the service, while six months of free twittering come with the $99 device. With monthly plans starting at $7.95 a month, it is cheaper than the upkeep for most Twitter enabled smartphones. Which is part of the selling point. The website brags:

“Best of all, you don’t have to spend $50/month on an expensive smartphone data plan to get Twitter.”

But it’s already possible to access Twitter from mobile without paying $50 a month. As one commenter wrote on the Wall Street Journal post:

“I bought my Razor for less than $30, and my data plan is 5.99 a month. And I can Twitter to my heart content (sic), all the while also having a phone.
Who needs another product to haul around?”

Also, since the TwitterPeek won’t have web access, users currently can’t see links in their tweet stream, which actually means it provides less functionality than most mobile Twitter clients. It also lacks search capability.

But this effort works more for marketing purposes. A device like this reminds people that Twitter is a mobile product.

Twitter wants more users. And further more, they want more mobile users. Amol Sarva, the founder of Peek Inc., tells the Journal that they’re targeting people who’ve tried the desktop service and been turned off:

“They tried it and don’t get it, but once they go mobile they realize how fun it is,” Sarva said.

It’s unclear if Peek will sell many of the devices. Sarva calls the TwitterPeek a “modest gamble.” But with nearly the same packaging and a slight tweek of the interface, Peek has turned its email client into a Twitter client. Hopefully, the didn’t spend too much money doing that.

Because it also helps expand Peek’s line of dedicated mobile services. If a Twitter addict wants only that functionality, they can get it. Just as the Peek helps those who need email but not a phone on the go.

So who are these Twitter addicts? Twitter and Peek are hoping that companies will employees dedicated to marketing on the service will find it useful. Also, a mobile device could help increase teen usage, where Twitter has been slow to catch on. But then again, what teen doesn’t already have a cellphone?