Advertising Other people's companies

I am looking for a freelancer to advertise my company and other companies by creating online ads that target the general public. Specifically, I need help designing ads that are professional in tone. I need someone who can create ads that accentuate our attributes and services in such a way that will create a positive perception with potential customers. I am interested in working with someone who is experienced creating online advertising in the marketing or advertising sector. The successful candidate must be well-versed in creating compelling and professional online ads that will draw attention and engagement from our target audience.
The job is pretty much making creative ads to other companies so their business can grow.