If you are using a CMS like WP there are plenty of plugins that will give you the analytical data that iTunes (stitcher et al) dosn't provide.
of course, all itunes does is provide a nifty UI for listeners to find your cast; it PLAYS off of your site. I wasn't satisfied with the "popularity bar" on my 'cast...cuz the what is it popular relative to? other casts in same category? all of them? ...
anyway I was already using "seriously simple podcasting" - a wp plugin to properly config my 1400x1400 jpg, my cast and all its meta-data so itunes could
crawl & play it.
make no mistake, this is not a plug; just the way I found that works easy; they have a tracking plugin as well - it tells me number of unique downloads and whether the users are using mobile or desktop to access (not much but way better than nothing) - number of downloads was mainly what I wanted to know.
As for improving your ranking; max-out quality and quantity, make it something people (not just in your specific peer group) would WANT to listen to. Same deal for blogs, be funny, be informative, be creative, be unique, be scandalous, above all BE INTERESTING or your newest listener won't rate, subscribe, or even comeback. QUALITY is the only legit SEO for pages, 'casts, etc.