Very interesting niche! I was just reading about this in a news feature article regarding companies that hire individuals specifically for this work.

My suggestion would be to gather some data and convert it to infographic form, showing the power of '1st page on Google' to influence perceptions. 'Everyone' isn't your market - quite clearly, it is people or products that have the public split, or that are not known.

Outside of the freelancing work and ads, another suggestion would be to join Meetups and attend conferences on PR. Perhaps even join a PR firm as a dedicated PR writer.

In short- you will have to create your position in the minds of the potential client.

I've spoken with nice startups about this sort of issue as their consultant, happy to bounce ideas with you on a call!

Warmly,
Arjun.