Still doesn't actually say what your service is supposed to be.

"Interesting" is not directly proportional to "Useful", especially not for anyone in particular. I'm not saying your service won't be either, I'm just saying that without more details, I don't feel compelled to be, at one point in the future, notified that this mysterious service I completely forgot about has finally launched its beta.

Give me something, anything, and I'll consider it. But "Hey, give me your email and I'll tell you when my random, indescribable app is available!" just doesn't cut it for me.