Quick and easy is NOT always the most effective way to go. Sometimes it is, in fact, the least effective. The yellow pages have been destroyed by search engines, and pay-per-click is a great way to waste huge amounts of money if it isn't properly maintained.
If you still think the yellow pages need to be a part of your marketing budget, then put a separate phone number in the ad, so at least you can track what your easy, expensive dollars are getting you.
The fact is, having a good web presence, printing decent marketing materials, and using a marketing calendar to get your message out there in a targeted way provide a far better plan. Yes, that plan isn't quick and easy, but it can be affordable and effective... two very desirable things in marketing.