Websites with email alerts services
Cold call, cold email
Contact companies you are interested in (mint), google, ask for advice, send ideas
Informally: attending events where they sell, asking family and friends for advice (or for contacts), with colleagues or ex-colleagues
Meeting people you don't know through events, courses, etc.
Give something so that if they like it, they are happy to buy more (freemium)
https://gojobhero.com/ free CRM for job seekers