Like any other type of specialist work, you can learn search engine marketing yourself if you have the time and patience to research and don't mind making mistakes. If you don't have the time to learn, or can't afford to make mistakes, it would be best if you outsource your SEO work to a specialist. But how do you know who to choose?

There are independent freelance SEO consultants, web design firms that offer SEO as part of their services, companies that specialise in search engine marketing and big Internet advertising firms that mix SEO in with their offering. The prices also vary widely. Although "you get what you pay for" may be true in some cases, more expensive will not always mean better.

Nor does the company/consultant you choose have to be on the MarketingSherpa How to Buy SEO Report. Although I think the report is very helpful you should not confine yourself to choosing from those few firms listed on it. In order to qualify for a review a firm had to derive a substantial part of their income from search engine marketing. That ruled out most web design, hosting and Internet advertising firms. All independent and freelance consultants were also ruled out as there was absolutely no way that the report could hope to cover them all, especially over the four countries that it covered (US, Canada, Australia and the UK).

If you choose to outsource your search engine marketing use some of all of the following points to help you decide who to use:

• How much can you spend? If you are on a very tight budget you'll have to cross a lot of the bigger firms off the maybe list.
• What else do you need? Are you only looking for SEO or do you also need web design/maintenance, hosting, online media buying, etc?
• How did you hear about them? Did they send you an email saying "we tried to find your site under its main keywords but it wasn't listed"? Stay far away from anyone who does this as they are spammers. If they don't mind sending spam email they won't have any qualms about using spam to "optimise" your site.
• What does the contract offer? Most consultants/companies will offer both packaged and bespoke SEO, but even though the package service will be cheaper and somewhat limited it should still be tailored to suit your site. So find out exactly what the package covers and how it will be applied to your site (ie: what exactly do they mean by "optimise the site").
• What is their spam policy? Use the list of no-no's on the spam page as a guide and ask them if they use any of those tricks. You want a long term search engine promotion solution, not some quick fix that will result in your site being penalised or banned.
• Did they ask you about your business and target market? A search engine promotion campaign has to be tailored to suit your audience. You do not want to use a consultant/company that assumes they know all about your business. Although they know about search engine marketing, you know about your business and market so they should ask you about it before finalising the keyword research and optimisation.
• How do they submit to the engines? All submissions to major international and local engines should be done manually if they are to be effective.
• How do they submit to the directories? Although you may be able to get away with automated submissions to some engines, there is absolutely no way you can successfully submit to Yahoo, LookSmart and the Open Directory using automated submission software.
• Do you own the optimisation? Some SEO consultants will design the optimisation and place it on your site so even if you decide to use another firm in future, the optimisation will remain in tact and your rankings and traffic will not be immediately affected. However, other companies will insist that they need the site and/or optimisation to reside on their server. Although there may be a good reason for this, it can also mean that if you decide to go with another firm they can effectively hold your traffic and rankings hostage as it is on their server and they can remove it from the web anytime they wish.
• Can they give you examples of past work? This is a bit iffy as some consultants/companies will not have permission from their clients to show examples of work or rankings.
• Does their own site show well? Again, a bit iffy as not all SEO consultants will spend time on their own sites. I've been trying to get this site up and running for over a year but just didn't have the time.

MarketingSherpa's Buyer's Guide to SEOP Firms
What to Look for in a Search Engine Optimization Specialist
Ten Considerations when Hiring a Search Engine Optimization Company
Positioning: The Good, The Bad and the Do-It-Yourselfers
12 Steps for Getting the Most of Your Search Engine Marketing Campaign
SEOPros - directory of companies offering search engine marketing
SEO Consultants - SEO consultants directory
SEM List - directory of search engine marketing professionals/companies