One of the reasons it has a hard time turning a profit is because it is often accessed by a multitude of 3rd part applications, and one of the most popular is TweetDeck.
TweetDeck smoothly integrates A user's twitter feed and facebook update feed. What it didn't have was a touch-screen friendly, iPhone-optimized interface. So, it was rebuilt from the ground up and now achieves both wonderfully.
I've been notoriously fickle about Twitter apps, preferring to sacrifice Facebook for less crashing, better access to links and pics, etc. with the native Twitter application. I've tried TweetDeck before, but crashes pushed me away.
TweetDeck 2.0 has solved most of these issues and made me an early, but not 100%, convert. However, I've already noticed some no-brainer wants for 2.1.
1. Position support - every other program changes when you turn your phone upright or on it's side. TweetDeck should too.
2. Timestamps - nothing I hate more than opening TweetDeck and not knowing if the "breaking news" tweet waiting for me was a minute or a hour ago.
3. Colors - you have themes on your desktop version. Bring them here!
4. Facebook comment fix - when commenting on Facebook, the screen doesn't scroll with you as your comment goes longer than the screen. Makes it really hard to write.
5. Hashtag bar - TweetDeck has a new wonderful follower bar for adding a twitter handle. Now duplicate it for hashtags.
Alright. Those are gimme additions. Add those and amaze me. For those looking to get onto twitter or get a new app, TweetDeck is on the recommended list.