A text listing in the specific city/country of your choice is offered to all international and national escorts agencies The free listing option gets you a permanent text link to your web site and and a few words to describe your agency, location or services (e.g. Beautiful companions for every occasion).
The only requirements that Open Adult Directory have is that their banner must be placed in a prominent position on your web site and the content of your site must be relevant to their directory (i.e. be escort related).
Free listings can take between 15-20 days to be reviewed and added if approved. Make sure to add their banner before submitting your listing. You can get your free listing here. They also offer an “Express” listing services that gets you listed within 48 hours and at the time of writing this costs $65. You can sign up for that here.