Most of what we do is real life networking in meetings where doctors attend. We speak at the events and are connected (because we set it up intentionally) with a number of doctor publications.
However, one thing we've done is look at their site and see what they need. If they have no social media for instance, go to fiverr to have someone create a FB fan page and plug in some likes. Then when you send an email or cold call, it's not just "we are an SEO/web design company blah blah blah". It's "here I noticed you didn't have this and I thought it could really help your business". "Can I have 5 minutes of your time to show you what else I can do for you?"
When you do that, you're invoking a powerful psychological trigger called "reciprocity". In simple terms, because you've done something for them first, they'll feel obligated to you in a certain sense. It's classic Cialdini. Especially because even though it took no time from your schedule, it seems like you've already done a lot for them. Most of these doctors are pitched with a fan page with a few hundred likes as a $2000/month service or more so you immediately 'stand out'.
Of course, there are a zillion things you could do for their website that they don't already have. The point is to give them something of value before you even move into the pitch. By doing that, you're immediately different and most of them will hear what you have to say.
From there, I've followed up with post cards and more stuff free if I need to. We're pretty specific with which doctors we target so it's not a "numbers game" like you hear. Target carefully.
Hit me up by PM if you have questions on how to do it.