Hi Ian Fraid my experience is years out of date. I started my sales by contacting room101, a web site based in Lebanon, for expatriates and persuaded them to include an article about my book - But to Let - The key Steps but my pen name Stuart Powers. I also persuaded about ten Waterstones shops to put the books on the counter - something they won't do now.
I sold just under 20,000 books (19,800) roughly half through Amazon and half through Waterstones. Getting to number 3 on the relevant list.
I don't think my book will work as an ebook on KDP as it has photos in it.
My latest book, Silvertown,'s Missing Son - again non fiction with photos will be issued through Amazon Select just as a paper back and I intend to try and get articles in local newspapers etc.
My feel is that the key is to follow the advice in Harry Binghams book, e.g. Get as many people as possible making reviews, market to the type of reader it will appeal to (by age, male/ female, genre etc), contact bloggers and web sites that may be interested etc. I think these things made more difference to my sales than people looking at seller lists but as I said mine was non-fiction and a long time ago.