I was just reading a post on the Google Webmaster Help Group about a site that the owner believed was penalized, and so he lost his rankings on Google. A senior member advised him that he should clean up his markup, as it was full of errors. The site owner was declaring XHTML 1.1 as his DOCTYPE! The guy blew the advice off, and used Yahoo and Google as an example of a site with invalid code being popular in searches. Well, of course those sites are, just by the sheer size of them! So basically, the guy offering his help "washed his hands" to it, but it got me thinking... How do you take constructive criticism? Especially one that can save your site from possible monetary suicide?