I don't have clear numbers on conversion rates before and after, prospects were from different segments and we kept changing our pricing and offer during that time to find the right fit so it's hard to measure. Before we brought him in we said we'll give him 3 months but it was clear we have a lot to learn and benefit after 3 weeks.
I wrote it on my spare time and based on my experience.
Nobody proofread it and it's a takeaway for next time. I posted it on HN since I like HN, that's all.
Emails and everything sent to customers were always proofread by a native english speaker. I wrote this on my spare time but lesson learned for next time.
OK, it is a trust issue. However you can use this library and change the proxy url to your own server and still get the benefit of the fact that you don't need to rewrite external requests and just use jQuery.
Regrading overwriting XMLHttpRequest, if it works - it works, and if it breaks it can be improved, this is why it is open source.
It does not reroute your site traffic just your cross-origin site traffic, which practically does not exist without this library. Yes it can be used to do bad thing but also opens up the opportunity for mashups, external content integration, api calls and more.
You can only use JSOP and CROS with sites you have control over or are designed to behave and support external requests. It makes it very very limited!
It's possible, we just make it easier. This library also make it seamless (you can still use jQuery.ajax). They can use this library and just change the proxy url.
It only goes through our servers if it's cross-origin. Normal http same-origin requests are left intact (and you can see it in the code). It's stated on the README but perhaps it should be more apparent.