The ideal way to obtain information about a the professional in question and their previous experience in the business is to acquire references from them. By learning what experience others have had with them is a pretty good indicator whether or not you can trust them. By examining these references and talking with the consultant you will be able to determine whether they have the expertise, knowledge and if they are a good fit for you and your business.
Now you may be hesitant to use a web optimization expert because the price tag on they services may be quite high. If you are like many business owners you do attempt to maintain a strict budget, especially here in Vancouver where prices for many things are high. Many of these consultants will work with you on deciding on a fair price, but be warned that in this industry cheaper is definitely not always better. This is an investment in your business and if you’ve chosen a true expert you will see positive ROI down the road.