To the others, I wouldn't think of this as a replacement for e-mail. E-mail is great for a majority of communications. Framing messaging from a historical perspective helps understand where our company fits.
Prior to the internet when you wanted to communicate with someone you had to attach value to that message. Whether it was a letter, long distance phone call, telegram, or other form of communication the cost and the time that it took to send were non-zero. The cost was also apparent to the recipient, which often had an impact on the recipient's likelihood of replying. The internet has done a terrific job unburdening messages of their cost and the amount of time it takes to send them. At the same time, it has created a problem of a small signal-to-noise ratio.
Consider a journalist who I would like to cover a story. With a list of 800 journalist's emails I can send 800 emails instantly. At the same time, with each journalist I am competing with hundreds of other message senders. This includes people with bad ideas for a news story who suffer no transaction cost in sending their messages. If I could communicate my value on the that journalist's time I could rise about the noise and communicate that idea more successfully. The system wouldn't be perfect, but I am betting that the overlap between people who place real value on a recipient's time and people who are offering value to the recipient is larger than the overlap between people who place no value on a recipient's time and people who are offering value to that recipient.
There's also a lot of discussion as to what these credits are worth. Right now, they're pixels on a screen. Scarce pixels. As we grow an ecosystem of message-sending, some people and companies may decide that they would like to purchase credits at a discount and offer to do things like paypal money or send discount codes for certain number of credits. At first though, the credits won't be the point. The point will be that we will provide a service for those people which will allow them to filter out people who place zero value on their attention.
I’ll address twitter sign-in quickly. When you log on to Gramicon the users who float to the top of your “find users” page are the ones you follow on twitter. Here is a list of people who you have already identified as interesting or notable. Next to their usernames you can see the average price in order to get a reply as well as their user-generated rating. Right now we only allow twitter login because we don’t want people signing up with facebook or their email and choosing the username kanyewest or stevecase.
Thanks and stay tuned for updates!