Its very hard to know. Some girls have someone else asnwering their phone so even at first base its hard to tell. One thing I am concious of when viewing a profile is a foreign girl with highly glossy pics and a "Hi guys" profile written in near perfect english. The odd bad english thing going on is more trustworthy. And the more glossy the pics the more Agency it looks - unless it is a known pro that can afford to spend the few hundred as a business investment. Pimps will not invest in an uncertainty and find it easier to put up fakes.