Responding to a lead from your website is important . . . how you respond is just as important. Are they ready for you to contact them by telephone . . . or email . . . or perhaps they feel they are "flying under the radar" and the response needs to be a very "soft" one. This can especially be the case if they are just supplying an email to receive something that you have offered on your site.

Michael Russer offers up a good article on "How to Respond to Online Leads" that is certainly worth the read.