Go to Best Buy or the Apple Store and ask a basic question, you'll probably get a stumped look or a wrong answer and a pathetic attempt to sell you a $99 HDMI cable or a $29 DVI adapter. Call your cable or internet company and ask if you're on the right plan and you'll get excuses and transfers and have to give them information that they already have, multiple times, and likely get an unsatisfactory answer. These places treat customer service staff as low-skill/low-pay commodity positions, and the results are predictable. Therefore, I want these fruitless interactions minimized, so self-serve it is.
My realtor, on the other hand, answers every question I ask. Maybe not immediately, but he will definitely find the answer and will definitely call me back. He even offers proactive information and next steps. I don't want to replace him with a website. And as a bonus, because he's pleasant AND knowledgeable, I actually want to talk to him on the phone, not even by email.
Summary: If you want "relationships" with your customers, focus on how capable the people they're talking to are, or replace them with a website.