Hey Phil, I don't remember WHAT exactly I changed in the keywords from version 1->2, but I'm pretty convinced that making the app prettier and easier to use was a key factor in the growth in popularity.

Keywords are one of those things you don't think about right away, but they can have a HUGE impact on search results in then end.

I'm curious - if the UI has changed - are people just picking this up from screenshots? With no trial mode, I'm interested in how you think improvments in the software improve sales. Note that I totally agree with this position, but I'm curious as to how this plays out on App Store purchases.

I agree with markrickert on this. Apps that look prettier and work better (usually) have more sales. And improving those things (usually) improves sales, as far as I've been able to tell.

Screenshots are part of it. Word of mouth is also a big factor. If people actually do like your app you'll have positive reviews -- it's commonly said that reviews/ratings don't matter, but for some apps they seem to matter quite a bit.