title: Price comparison websites - how do they work?
body: <p>I was just wondering if anyone could explain to me how a price comparison website works? I mean if it works how I think it does (explained below) then I have a really good project to work on for myself, which should make a lot of money long term.</p>
  
  <p>So how I think it works is that each supplier provides an RSS feed which the comparison website connects to. Each product has its own unique code (provided by the manufacturer) and this is supplied in a standard tag in the RSS feed. The comparison website collects together data about who supplies which product and compares the ones that do supply a specific product. For example, book publishers may provide RSS feeds containing the blurb on the back of each book, the ISBN, publishers name, authors, title (obviously), RRP, genre, fact / fiction and some other useful information, all in tags such as &lt;ISBN&gt;ISBN here&lt;/ISBN&gt;. Comparison websites which sell books may filter these books by genre, author etc and display them how they want using an xsl stylesheet (the RSS feed being provided in XML).</p>
  
  <p>Is this correct, or do I have completely the wrong idea of what RSS is or how it works? What other ways are there to achieve the same thing?</p>
  
  <p>Many thanks in advance.</p>
  
  <p>Regards,</p>
  
  <p>Richard</p>
  
  <p>PS if this is tagged wrongly and should be moved to another section then please could someone retag it. I tried to find price comparison websites or something similar but theres no such tag. I have put the most relevant I could think of.</p>