For example, you can view all beauty salons in a certain area of the city. On the Internet there are many mailing lists that are devoted to different themes. Real Time Bidding), allowing to arrange the bidding in real time. These parameters can then be adjusted according to the results of search engines.
Exist-open mailing list (for everyone), private (for people of a certain range), free (existing due to the enthusiasm of the creators, sponsorship, paid advertisers), paid.
Keeping up with a single step from the pace of technological progress, advertising day by day becoming more professionally organized and more efficiently executed.