We have a fairly standard eCommerce marketplace site.
When a user searches for "something in city A" a friendly url is created with that search term which displays a list of products for that term. These pages are then indexed by Google and subsequently crawls the product pages. It has resulted in us having many more pages indexed than we actually have products.
My question is. Is this a sensible strategy? Are these considered doorway pages by google? Would we gain an advantage by using sitemap.xml with links to each product?