Rather than have a link on my site, I gently ask clients and customers if they can spare a few secs and take the time to write a review on Google Local, particularly if I've gone that extra mile and they already have a Google account.

I'm not too sure what ranking weight reviews have in Google Local, but besides this testimonials are great social proof and not surprisingly a number of new clients have mentioned testimonials on my own sites.

I sell software and the conversion rate since I added testimonials into the main body of the page rather than the sidebar has gone up dramatically, not just for sales but also for customisation requests.