How Do I Advertise to Businesses Online Without Spamming?

[Curious]

I am handling the advertising online for my stepfathers' tow truck business. I have a website that is on the first page of Google and Yahoo for local towing businesses. I also advertised the website on classified ads and business directories. What other ways can I try to get the attention of local businesses without spamming? I know I can't email them offering my towing business service-it would be considered spamming.

[Eddy]

don't no one cares about ads on the internet. honnestly

[Peter Nikolow]

Try to create videos for YouTube - this also penetrate search results.

[Jake]

Who selects the towing service? it's probably not always the car owner, insurance companies, police departments, garages all may have towing companies in their Rolodex, some have commercial contracts, it's probably worth courting some of these potential contacts, there are sites that imprint your info on Promotional Gifts, like pens, mugs, etc. (I image in the big city bribes are passed out)
I trust you have a business address enabling you to claim local (Places) listings on Google/Yahoo/Bing citations on other business directories as well as customer reviews on the pages used to be ranking factors, now, your main business site ranking may be a big local listing rank factor.