What are those "Quote Service" and "Pre-Screened" Contractor referral services?
These are nothing but advertisers that refer you to roofing contractors in your area. They do no roof work themselves and likely know nothing about roofing. They simply pass your name on to other people.
How are contractors selected for these services?
Most claim they carefully select their contractors. When Bert Roofing was approached by these web sites, they did very little checking and allot of selling. When a contractor obtains business from one of these sites they are required to pay a commission back to the site. Now just how critical do you think these sites are when every contractor they recommend is essentially their business partner?
What are some better methods of locating a contractor?
Since you are already on the internet, visit the Roofing Contractors Association of Texas and look for their "Certified Roofing Contractors". All these contractors have been in business some time, have insurance, and have pass written examinations to be certified. Also try the North Texas Roofing Contractors Association.