Joseph here, cofounder of HelloSign. e-Signatures are legally binding. It's more of a cultural attachment that keeps us using "wet signatures". Check out our legal page for more details: http://www.hellosign.com/info/legal

In terms of making it more widespread, it takes some work.

The way we're doing it is by combining e-signatures with other services and doing user education and cross pollination between the services. Our other product is HelloFax, which lets you send and receive faxes online.

But, I think we're getting closer to an inflection point as society is starting to use e-signatures more and more.