In general, any and all feedback is very helpful to the development of Oovium. It not only let's me know what is working and what is not, but also energizes my development.
Ratings and Reviews also have a significant impact on sales. Increased sales allow me to focus solely on Oovium (as opposed to being distracted by other more lucrative projects). This of course can have a significant impact on how quickly Oovium progresses.
One unfortunate aspect of the review mechanism for Oovium is that every time a new update is released the app's rating is reset to it's lifetime rating until the new version receives 5 new ratings.
In a highly questionable move, when I first released a very very early version of Oovium in November of 2009 (before the iPad even existed) I made the app free. At this time, Apple was automatically requesting ratings for apps whenever they were deleted. The combination of a highly unusual app; an admittedly early and fairly rough around the corners version; free downloads and overzealous rating requests resulted in the 38 or so 1 stars it has received.
Consequently, every time a new Oovium version gets released, all those 1 stars from 2009 get recycled. So, yeah, in short... rating, reviewing and refreshing those ratings and reviews is much appreciated!