First of all – familiarize yourself with basic SEO jargon like: internal/external links, meta tags, titles, pagerank, etc. 

This way at least you know what the SEO company is talking about when they make the sales pitch.

Personally, I noticed that the shady ones are often hiding behind geek lingo trying to paint you in a corner by throwing these words at you, thus proving that they know what they are talking about.

You can cut that conversation short and find out how credible and professional they are by asking 5 little questions. Here they are:

1. What kind of results should you be able to see and how long will it take to get there?
2. What experience do you have in my industry and how long have you been doing this?
3. Show/send me examples of your previous work and success stories. Can I contact some of these people?
4. Do you follow the Google Webmaster Guidelines?
5. What other marketing services do you offer besides SEO?

Just keep this list by your phone and take notes while they answer these questions. I’m sure you are a pretty seasoned business individual so you should be able to spot the shady ones right away. You can download a quick and easy PDF document of “Questions to ask a SEO company” right here.