Sttop thinking about advertising products (Google, Facebook, etc.) and focus instead on the following sequence of questions:

1. Who are my most profitable market segments? Go through your existing customers and look for things in common with respect to profitability of clients, this will give you the best bang for your buck if you can target those people. If you're targeting the wrong people none of the rest matters.

2. Where do you find them in the greatest concentration? Pay attention to where you can find these people, who else do they buy from (possible joint ventures or host beneficiary relationships), what do they read or watch, are there lists of these people, who do they look to as authorities, etc.? The more concentrated you find the the lower your costs will be since in effect you're paying per impression.

3. How do they buy? You want to mirror their buying process so if they go online and do a search for a particular keyword to make a decision you want to rank for that keyword. Maybe they are looking for certain characteristics when buying so you want to match those characteristics. Maybe they trust a certain authority so you want to be in with that authority. Or maybe they look to friends so you want to create social awareness.

These will give you information about places to look (newspapers, magazines, Yelp (it's free to list yourself so you should be on there for local marketing), online directories, review sites, maybe in the media, maybe appealing to various micro niches such as body builders or models or wedding parties. The key is to filter through those 3 questions to maximize your ROI and effectiveness.