I used to use Facebook options such as, Page, Group. and making events to invite 3000 people who were in my friend list to introduce my new services to them and it was very good at that time, many people would see my advertisement and buy my offers. but Facebook is now fully useless for doing these, because it limited all of the options to do any sort of free advertisement to almost zero, and event when you pay for ads it doesn't work well. it's just waste of money. I also have an Email Newsletter but it has only 1000 members and I'm sure most of them don't check their emails to see my offers...
What is the most effective method to find people who maybe interested in your services, making a database of them and announce them every time you have a new offer?