Yes marketing online is the most effective way of marketing!
But remember, your offline customers are going to be your customers with a bigger budget.
So I have many online customers and I have gained many offline customers through craigslist. But the best paying customers are ones I found paying for yellow book ads, had a website but wasn't ranking, and I walked right into their office with a business card and a personality.
In the beginning I offered a free competitive analysis right there in front of the client. And that was my hook.
These clients are on at least $1000 a month retainer. I now outsource everything and play on my computer
needless to say.
Now, once you are a large corporation, you can be online and charge whatever you want. For the small people, we are forced to give deals to online customers as SEO and web work is out-sourced to developing countries. It's why I outsource. i.e. YOu can get articles written on the web for $1-$5 and I've found some decent article writers for that price. I can't compete with that, nor would I want to.
So there comes the conflict of working for less as web consumers become more internet savvy. Then again there will always be the skeptics that like to deal face to face with people.