Suggestions for marketing a Twitter app to new users

Technical Background: I have an application that relies heavily on the Twitter API. This app is genuinely very useful for Twitter users across the board but especially for Twitter users who want to promote substantive content. The application does a similar thing to an existing Twitter feature that many people use but with a tweak.

I have a few issues in marketing the app that I need help with:

Explaining features or benefits: How do I get people to see the greater context of what the application offers without their reaction being ".. but I could already do that with Twitter". (I think this is going to be the toughest challenge to overcome).

Promotion: How do I go about promoting the site's link on Twitter? I have few followers though I think I can get up to two high profile Twitter users (1000+ followers) to promote the link for me through a one-off message to their followers.

Going viral After launch, should I start promoting the application by sending links and emails to blogs and websites? (e.g.: hackernews, techcrunch, reddit, ...) or directly to Twitter users?

Last question : what kind of customer churn rate would be acceptable to catch the long tail hump? My intuition tells me that if I can send 1000 links to get 100 people to try it and from there get 10 persons out of them to promote it(90%), the product is in good shape to become viral? Am I off?

I'm not looking for the perfect answer just some crowd-sourced ideas from you and tales of similar experiences.

I have receive some suggestions but I'm even looking for more feedback.

• send the link to as many Twitter users as humanly possible using @user (message), but send the link unobfuscated to separate oneself from the spammers who use the Twitter t.co shortener in combination with another shortener to hide the true link. The application URL happens to be short enough that it doesn't even obfuscate to T.co but I'm not sure even if this is enough to get people to click on a link from an unknown and untrusted source. Would you click on this link?
• Use the Twitter users own name in the link you send them. This could be both a turn on and turn off. Personalisation is always good for promotion but this could be seen as coming from a spammer with a little PHP programming experience. (Though maybe I'm giving the average Twitter users too much credit for knowing about programming and URL re-writing)
• Send the application with a personalized message to all of the Occupy Wallstreet protesters using Social Media on Twitter. The application would be especially helpful for this crowd. Who are some of the other users on Twitter who are on Twitter to spread messages, links and content that I should be aware of that would benefit?
• Reach out to Twitter users offsite, on other service like Klout.com. Where else do promotion minded Twitterers go and "hangout"?

Thanks in advance.

Regarding your first question: Tell them. Having looked at your home page I have zero idea what your product does beyond what FB's link to twitter already does. Maybe a very simple comparison chart?

You have a link to a "guide" which asks me to log into fb. Why? First off the word "Guide" implies that this is complicated. Second, why isn't that content completely available on the home page of your site?

Which leads to the next thing, if your service requires a Guide to figure out then it's already too complicated...

Next you say "This app is genuinely very useful for Twitter users across the board but especially for Twitter users who want to promote substantive content "

I'm having a hard time understanding that part of your statement.. If your app helps promote twitter content, then why exactly are you asking how to promote your ... well, twitter content app promoter. Which leads to my previous question: what does it actually do?

Think about how you would explain what you do in an elevator ride to a 35 year old soccer mom. You have 30 seconds to say maybe 3 things about it. Write that down and put it on your home page. I guarantee that will be 1 million percent more important than having a picture of a giant bird flying an airplane.

Next you have a large part of your real estate devoted to having them enter their twitter username. I have no idea what it's going to do next. Is it going to tweet something for me? Will it kill a kitten? Is it going to scavenge all of my previous tweets and move them to google+?

Google can get away with just having a box with the word "search" next to it. That's obvious as to what's going to happen. You have a box asking for my twitter name with an OK button... which will do what?

The above isn't meant to be mean or discouraging in any way shape or form, so really consider the following two statements: You appear to have mastered the art of obfuscation, fix that. My advice is to take a page from twitters playbook and describe your product in 140 characters and put THAT prominently on your home page.