I created flatlaw.ca in 2013 shortly after starting up my law practice. It's now one of the highest ranked sites for many fixed fee-related search terms on Google. As of June 3rd, there are 100 lawyers advertising 551 fixed rate legal services products.
This blog post contains some of the statistics for the site over the last couple years.
Key Stats From Last Two Years
Sessions/Week From Last Two Years
Weekly Users Over Last 12 Months