I've always been sceptical that simply adding things such as sitemaps could improve Quality Scores (most my sites already have them), however I tried a new website earlier this week and the Min Bid, when checking in Adwords Editor was surprisingly pretty high ... 0.20. I added a Sitemap and linked it at the footer of the homepage and I come to check it today and it's now 0.03. Quite surprising, and not sure if this is just a random change due to an 'average' CTR or, whether adding the Sitemap has improved the landing page to such a degree. Your thoughts?