Have you made it easy for people who visit your website to identify themselves and request more information while they are visiting?
Consider placing an "Information Request" navigation button or link on every page, which takes the visitor directly to an information request form.
To entice them to fill out the form, make them an offer they can't refuse (free newsletter subscriptions, free exhibit passes for upcoming trade shows, a free mug, poster or t-shirt, email notification of website updates, etc.).
Be sure to include a few qualifying questions to learn more about their needs, timing, application and purchasing role.