Basically, Welcome and Introductions is for your first 7 days here. If you have a post in Houston, you shouldn't do one in Dallas.
From the advertising guidelines:
The "Welcome and Introductions" forum in each Metro Location is an excellent 'landing pad' for new ladies to the community. These sections have excellent readership from the members in that particular city. New ladies are welcome to make a post in this forum during their first 7 days of membership. This will be called their 'intro ad' and may include all their details, info, and pics. This may be done before you have requested VP status or while you are waiting for approval. Once approved, however, please use the appropriate forums to advertise and post in this forum only to welcome new members.
As a Verified Provider, you have advertising options open to you, including ads in up to 5 cities per week, if you are providing services there.