You can make your marketing materials more effective by including a call to action and a website address on your print and emailed materials, and then creating your website to offer more information and help the sale along to the next stage. Depending on the offer, your client, and the price point, the website may – or may not – be able to make the sale for you.
You've probably seen this in action on postcards and flyers. But, don't forget to use it on brochures, and even on your business cards (the back side is perfect for that). And, you can put a call to action on the bottom of your email, and use links in your email newsletters.