The service sounds interesting, although the pricing is way too high for me (more on that later). I apologize if I sound harsh in my feedback, I'd be equally harsh to one of my own projects too. That said:

1) The color you've chosen for "pub" (#FFF191) doesn't contrast with the white background enough. I find it hard to read. The same problem arises in reverse on the "Free Trial" badge.

2) "A dead-simple messaging API and web service" doesn't do it for me. I still have no idea what your product is.

Spell it out for me:

"Get your app talking to Twitter, AIM, and Google Talk in 5 minutes."

3) The goal of the homepage is to tell me what your product is before losing my attention. The best way to do that is getting me to watch a video. Make your video the center of attention on the homepage and optimize for getting people to watch it.

4) I like the bullet points, but just stick with the first set (no animation). I would also remove the last one, "A cost effective solution!", as it sounds like you made up a 5th item to round out the list. I would also make the copy more active.

5) The upgrade IE6 message is inappropriate for a business website, especially when trying to sell a web service to web developers. You're trying to convince me that I can trust your library to handle all the nuanced use cases that would take me weeks to discover. Remember, I'm a developer so I'm looking for a reason to write my own library - don't give me one.

So if I see "function showUnsupportedBrowserAlert()" in your Javascript it says 2 things to me:

- Your site doesn't render correctly in IE6

- You don't care enough to fix it

That's doesn't give me confidence in your messaging library, which is far more complex than HTML/CSS.

Also, suppose someone does come to the site with IE6, or a browser incorrectly identified as IE6. You're effectively turning them away, is that really what you want to do? What exactly is broken in IE6 and what would it take to fix it?

6) The video on the homepage doesn't perform well as a sales tool (I'm not sure if it was meant to).

I'd make a video that starts with you typing a message into an example app and clicking send. Then your AIM, Twitter, and GTalk alert new messages while your phone rings to play the message back with surprisingly high fidelity. Then show me the 2 lines of code it took (but don't show the install process or have me watch you type out code).

7) Pricing - I'd switch away from using different prices for Email/GChat/AIM/Twitter. Even if I'm a current customer it makes them too tempting to replace one by one. If I'm already integrating with your web service whats so hard about integrating with theirs?

If its feasible I would include a ton of free credits for those services in a monthly subscription, and make your money charging for SMS and speech-to-text over the phone. SMS is a traditionally expensive technology, and both it and phone are much harder to implement than a web service.

I might also change from 1 cent per message to $1 for 100 messages. To me it sounds cheaper, even though it isn't.

I'd also provide a way for your website to call me with a message I've typed in to showcase your text-to-speech accuracy.

That's about all I've got. Best of luck with the service!