Remember that if you're looking to do service-based client work that it's always about relationships: with clients, with prospects, with leads, with referring sources, etc.
Online can make building those relationships easier and more accessible more often. Honestly, I would combine on and off line. Just be sure that anyone you meet offline you also find and connect with online to nurture the relationship you've started.
There's tons of ways to generate leads online. Just keep in mind that they all flow back to people having access to you. I've been designing websites and coaching/teaching my clients all about marketing and converting online for more than a decade and I've not once had a client who came to my website, found a 'buy now' button for my services and paid me without first talking to me.
Marketing/selling a service is different than a product. With products your conversion is list signup and buying - that's it. And the list signup leads to buying.
But with services you have two conversion points - one from marketing and a second from sales. The first, from marketing, gets people to engage with you - email, phone, in person, etc. They get to meet you and sense for themselves whether they want to work with you. Then, the second conversion point is the sale. That's when you work through a conversation toward a purchasing decision.
Service providers have to do both - build leads and then convert the leads into paying clients. So don't shortcut either process. And be clear that something like a website isn't there to 'sell' your services. Rather, it's there to generate leads. You, on your sales calls, will be the one who generates sales.
Along with all this, it's really helpful to read a couple of good books about selling if you have any confusion around it. I'm one of those sort of naturals at it but even so I've read a ton on sales and negotiation. The bottom line is be comfortable with the sales process and know that the biggest secret to sales isn't in what you say it's in how well you listen.
Above contributed by Dawud Miracle