If they offer linkwheels, blog commenting, directory submission,social bookmarking, write articles that are full of largely outdated and inaccurate information then submit them to press release sites, they don't have a clue. that is a good place to start and should weed out the bulk of the services section here on DP. hope that helps. Happy to answer questions after lunch Nigel
What Nigel said and look at some sites the SEO worked on to see where they rank for their keywords ...
I TOTALLY agree... Nigel you rock! I would only add a few other dead giveaways that the SEO probably sucks... 1) When the SEO says they will guarantee you a #1 ranking for any keyword... 2) When the SEO says you need to optimize your meta keywords to increase your rankings... 3) When the SEO calls a <title> element a meta tag... (If it doesn't start with "<meta" then it's NOT a meta tag... err... element... Oh wait that's another... If they don't know the difference between an HTML element, an HTML attribute, and a starting tag and ending tag)... 4) When the SEO is willing to work for $3/hr... 5) When the SEO calls a link "a PR8 link" because the home page is PR8 although the link is 10 clicks away from the home page on a page that is not indexed and displaying "Page not currently ranked by Google" in the tool bar... OMG I could go on... but I want to share the fun and let others come up with some, too!
When the person runs a SEO company ( you can see it from his signature), but goes around asking noobish questions in forums such as this one.