Certainly, when you're evaluating a person or company, you can (and should) ask for references. That will certainly give you some insight about their history with a few select campaigns. But most people (and all companies) that I know are most likely to point you in the direction of companies that they know will give a positive reply to the request for a reference.
Getting an Unbiased SEO Audit
There are some individuals and companies who will provide SEO audits. But, even these folks are a bit biased. Chances are, this is an opportunity for them to earn new business. If they tell you that your SEO efforts stink, who do you think they'll suggest you turn to in order to get things "back on track?"
This is why there are so many "consultants." You know, the guys that are paid a big fat check to develop piles of paper that makes it appear that they've done a lot of work. Once they've made the impression that they're really smart, the chances are very good that a company will turn to said consultant and ask, "How do we get these issues resolved?" So, this consultant either says, "I can do it," (for an additional fee) or "I know a company that specializes in this area" (and they are paid on the back-end through a referral check or commission).
Let's get back to the SEO audit that you might get from another SEO firm. Try to put yourself in the SEO firm's shoes: You're being given a great lead. This company didn't ask for an SEO audit because they're happy with their vendor. They're asking for an SEO audit because they want to justify their feelings and have something to back them up when they recommend a change.
I recently spoke with a friend in the SEM industry about this, and what I heard wasn't surprising (this person asked to remain anonymous). This person told me that they had one of their campaigns reviewed by an auditor and this auditor ran into them at a conference and told them as much. This auditor went on to say "I gave you a glowing review." My friend was concerned about this auditor doing this, because there was a known history of spamming the search engines.
So how in the heck do you get an honest opinion or honest and good feedback on whether your SEO efforts have a passing grade?
I'd like to say "you can always trust me," but that's the problem with the SEM industry. I'm biased. Of course, I want your business, right?
What You Should Do
If you really want an honest opinion of your SEO efforts, get multiple companies and/or individuals to perform an SEO audit. Tell each of these companies/individuals that you aren't leaving your vendor. Tell them that you have a long established relationship with that vendor (or, if you do your SEO in-house, your employee) and that your intentions are merely to get additional eyeballs on the project.
Here are some things you'll want to make sure are a part of your audit:
- Search Engine Reputation: What is your opinion of the site's overall search engine reputation (PageRank, rankings, traffic, etc.)? Ideally, the auditor can review historical data to see what effect your SEO efforts may have had on organic search traffic. ROI should be measured on an increase in relevant/quality search traffic increases. If you know what a visitor is worth from your paid search efforts, you should have an idea as to what a visitor is worth from SEO efforts.
- Search Engine Exposure (against keyword competitors): What is your opinion of the site's overall search engine exposure (number of pages indexed, etc.)? How does this compare with other Web sites ranking in the top 10 for the keywords targeted?
- Web Site Structure: Does the Web site have a "search engine friendly" structure (navigation -- text/image-based/Flash; URL structure -- keyword usage/dynamic; header tag usage; textual content per page; sitemap; robots.txt)?
- Link Popularity: What is your opinion of the site's overall link popularity? Does the site need more links? More on-topic links? Are the links of high quality (looking out for link farms)?
- Internal Link Structure: What is your opinion of the site's overall internal linking structure?
- Site Meta Data: What is your opinion of the site's meta data (title tags, meta tags, etc.)?
- Domain name: What is your opinion of the site's domain name, and other domain-related factors (domain age, other domain names)?
To assist you with your SEO audit, I've developed an SEO Audit template. This will make sure that you're requesting the same information from each SEO company or consultant, and you're able to get a reasonable consensus on how well your Web site is optimized.
I recommend that you get an odd number of respondents, so that you don't end up with a tie (half of the SEOs think that your optimization efforts are solid and half think they're terrible). If you plan to pay these respondents (and you should), they should provide some actionable tips/suggestions on what they would do.