There are many factors that make an Search Engine Optimization campaign successful. Of course you have to hire the right company to start with. There are many companies jumping on the SEO bandwagon that are inexperienced and what I refer to as “Message Board SEO’s”. They gain their knowledge from various SEO message board and forums that are scattered across the web. The problem with this approach is much of the information that they gather is incorrect or speculative. In their quest to rush into this business, they get much of it wrong. Applying incorrect techniques coupled with no real world experience will surely end in a failed campaign not to mention the complete waste of time and money. I can’t tell you how many times we have to re-educate customers that had poor/no results with other SEO companies.
Unfortunately, undoing the damage of a poor SEO campaign can be costly and time consuming.

Assuming you have hired a seasoned SEO professional with all of the technical expertise needed, there are two more important aspects to consider.

1) Customer involvement
2) Trust

Customer Involvement

The most successful campaigns have the site owner or person responsible right in the middle of the decision making process and taking prompt action when needed.
Some common actions items are:
Thoroughly reviewing the initial keyword phrase research
Work with the SEO professional to select the correct phrases for each page to be optimized.
Copy revision/addition on pages to get optimization correct
Ongoing search for inbound links from relative sites
Writing articles blog posts and press releases
Constantly updating and expanding the site
Social Media Involvement

While many SEO’s can do all of the above, (for a price) the bottom line is if the customer has a hands off attitude, they will most likely be disappointed by the results.

Trust the SEO Professional
Trust is essential. The customer must trust in the company/ individual that is optimizing the site. The SEO professional will typically have many request and much advice for you. However, some customers don’t listen to or follow the advice that is given. SEO involves a hefty amount of on-page and off-page factors to be successful.
They may ask you for permission to do things that you don’t fully understand. Don’t be afraid to ask why a particular action item needs to be done. This may involve work on your part or the SEO company.
Top requests that are ignored are:
Blogging. Setting up and maintaining an onsite blog
Social Media participation for their company
Video. Having video as part of the sales channel
Submitting press releases and publishing articles
Testimonials
Restructuring site to be more search engine friendly
Bottom line is, the customer that trusts their SEO partner and follows their advice will be much more successful in the long run.