I have seen a few ads that ask for a description of yourself along with verification info.
Is this for the reason of knowing who is at the door that day?
OR are they being selective?

some ask because they are of a tiny build and frame and just can't do anything with a very large man.  Some do it for knowing who they should be looking for on an out date or to arrive at their peep hole on their room.  Others do it with the age factor as they are uncomfortable seeing someone under or over certain ages.  The issue is many guys(I have heard) lie about their info because they are afraid of being rejected(age and weight are very common for this one) and unfortunately it can lead to a very uncomfortable session for the both of you.  Best to be honest so you do not waste your time and money with someone who cant even begin to appreciate a person outside of their comfort zone

Makes sence, the size think and all.

i posted my pic on the site when i joined..when i request an appointment..they can see what they are getting..takes all the guesswork out of it..works for me..

I have had providers Google my name and do a search on Facebook.  I haven't provided this information to them, they simply do it for their own protection.  I have also been viewed on Linkedin.

Interesting, I actually facebook applicants before I call them for an interview.
If I am looking for a bartender the last thing I need to see is pictures of a party animal doing stupid stuff

The company I selected to build my website has this question included in my screening form. I also have the option of adding/removing questions. If I counted correctly, there are 36 ethnicities to choose from. Lol. However, I do not use this question to be selective. I use it to verify the information I am given. I enjoy meeting new friends from various places of the world. Size, shape and color does not matter. Professional and respectful gentleman are always warmly welcomed!  

It is for the ladies to stay safe and know who they are dealing with. I personally feel a lot safer when I do screen and I don't allow exception. just be careful of ladies that ask you unnecessary questions and sound unprofessional