I don't know about 100, but my very first three clients came through thought leadership articles. I believe that referrals and SEO kicked in after that for a good mix of sources.
Smart marketing through relationship building on social media and SEO. If you are a purely click through online marketer, your relationship building will be within your funnel and email campaigns. If you use the internet to build connections that you then take offline, obviously you will want to build into your funnel a step that includes a phone call.
Emails and Direct Mail,usually difficult for most to believe. Bought every book I could on the subject of selling and embraced the gift. Over a period of time I've become rather good at the content creation, the email funnels, the service packaging and of course the customer experience improvement. I am an Experience Designer, I focus on Design of Utility Products, Customer Engagement, Growth Hacking and Customer Experience.
The Secret behind it all is a mind shift change. Focus on making your clients' money, that will get you paid very well especially when they make money.
Picking up the phone and asking people if they had a problem that needed our solution. It was that simple. Would love to discuss more if you're interested.