Websites.
Everybody goes there first.
99.9% of your potential buyers are on-line. And, like it or not, the vast majority of those will visit your website before responding to your marketing. So make it a link in the marketing chain, not the end of the line. Provide more information than an ad, but less than your fulfillment materials. Craft the site to force an inquiry or you'll lose the lead.
Create a visual, emotional presentation. Make the site interactive. Use it for special offers. Refresh the content frequently so prospects will return. Feed the leads into your customer relations management software. And follow-up as quickly as humanly possible.