Social Proof: Try adding testimonials and customer logos. You would be shocked by how many people fixate on these items.

Microcopy: Let a users know what exactly will happen after they submit a form. Remove any anxieties.

Branding: Make sure your landing page, form, or microsite feels like your website. Give you the visitor assurance by using your logo and sticking to the style (font, colors, etc.) that make the user feel at home on the rest of your site.