Direct mail is also an option. This is one of the traditional ways of promoting and it still works. Not as well as it used to, but it has its own justifications.

The price of contact is higher then any internet contact, but a hard copy exists and a lot of people still prefer to receive something in mail then their email.

There are many lists of contacts and many companies selling them. One other option is also adding your website and email address to any of your mailing materials.