How do you evaluate a search engine marketing service? We've blogged about this before, but there is just so much junk on the Internet related to search engine optimization, I wanted to cover it again here.

First, be sure you understand the difference between link building and SEO. These are quite different in my eyes. Both are necessary, but I find that many of the web sites that are selling a search engine marketing service really just dress up low-quality link-building and call it affordable SEO. This strategy does not work anymore. I doubt it will hurt your site, but it just won't make any difference to your business.

So what are the selection criteria for a high-quality search engine marketing firm?

1) Fortune 100 clients: Quality tends to breed quality. And large firms are able to put in the time to complete appropriate due-diligence. If you find a search marketing firm with big names you recognize, this is good. It's a sign that those big fortune 100 companies went through their procurement process and determined the firm was high quality.

2) Full transparency: With so much bad information and confusion in the search marketing industry you need to select a firm that will give you detailed reports of exactly what they are doing. This is good for several reasons. First, it helps educate you on how the Internet works. Second, you have the data to be sure that you are getting what you paid for and are within the Google guidelines.

3) Focus on results: You want a team that is accountable and results-oriented. The search firm you are talking to should easily produce past success stories for other clients. However, when they do, bring a skeptical eye to the results. We get pitched all the time from firms saying they can put us on page 1 of Google (something Google says is not appropriate to promise ever). When I ask for examples of past performance, they produce a phrase like "buy a washer in Cleveland" as evidence (this was made-up to make my point). Well, that's really not appropriate. One well-placed blog entry could rank on that term in 24 hours. Be sure you know how to evaluate what they are telling you.

In summary, you should use the above criteria as you evaluate a search engine marketing service prior to purchase. Don't jump at the first offer you see and if you need help understanding what they are saying ask questions.