Choosing your contractor can be a bit of intimidating task and one should always do the research before even making phone call. Because I know about this tendency very well I always implement recommendations on my website, making them easy for potential customers to find I optimize my chances of being selected.
Recommendations from Facebook are always great, if you are using Facebook correctly you can reap benefit of this service and additionally if you are customer searching for you trades man on Facebook can show some valuable images of his work and furthermore some additional information on how he did on his previous jobs.
I know that many new customers of mine have checked me on Facebook before even picking up phone to book the appointment and this is only showing that potential customers are doing their research before hand and by this they can know what to expect. If you have some very good position on some review portals, then it will be fantastic for future business.
On the side of Customer searching for professional, you can find most reviews on yell.com yelp.co.uk freeindex.xo.uk and other services. Some business claim to be number one on some review websites, however often those websites would help only few companies in their niche and this being not very comparable metric for customer.
If you have any recommendations in this matter, simply leave your comment.