You will see results between 2-6 months. Timing will depend on the following:

Branding:
How does your brand differentiate itself from its competitors

Knowing Your Target Market:
Have you identified the ideal client that your company would like to target

Current Marketing Campaign:
It will depend on whether you currently have keywords ranked with Google. If you are running an email campaign, content creation, social media, ppc campaigns.

Go-To in Your Industry:
Are you the company in your industry that people recognize as an expert?

Current Clients:
Do you have a current base of happy customers that have submitted reviews and follow you and social media and have subscribed to your email list?