Once the visitor enters their details they will automatically be redirected to the 'thank you page' to claim their free gift, report, voucher, etc. It is a good idea to also place a 'call to action' on this page, ie give the prospect a reason to get in touch, such as:
"Sale Ending Soon - Call today for an extra 10% off all Widgets" - or similar.
This page can also be used to educate the prospect a little more about your product or services and how they could benefit.
Our studies show that a system like this improves conversion rates drastically, massively increasing the likelihood that your website visitor will actually call you, meaning more business for you, and if they don't call right away you can follow up, either in person or with a series of emails sent out automatically designed to nurture your lead until they are ready to make a purchase.