I would pick up the phone. I think actually speaking with the decision-maker will illuminate how to reach them at scale, objections, and other things you need to know.

You have to give it away for free to get started. I'm not sure you can charge any one anything for you to build your website and help them "possibly" make money in the long run. That is super hard to pitch in my experience -- and sounds rather self serving (if it is really isn't).

Figure out a way to build the website and then charge 20% for leads. That's a more credible model.

Hello. It's been a while, so perhaps you already have your answer? My two cents: I don't want to discourage you, but this is a pretty crowded marketplace (Angie's list, Yelp, ClubLocal, Home Advisor, Thumbtack, etc). It takes a lot of marketing dollars (and/or a great product/service) to fund consumer awareness building.

Small businesses also don't usually fork over $200/month (that is a lot of money to most) for an untested service.

You might try a lower entry point for the businesses and start smaller (10 businesses). Just call a few businesses (have a sales website, email, PDF overview ready first) and see if they have any interest. Most contractors these days pay either per prospect lead or per transaction. Paying for "impressions" PLUS revenue share (how are you going to track this, BTW?) might be more than they are willing to risk on a new venture.

Best to you!