If your website is an ecommerce website then just try to introduce offers on your website. Add some coupons and discounts which will help to attract visitors on your website. This is the best of direct marketing.
Sending message to high targeted, interested people via email. As far as a list of active customers is really hard to build or find, it's better to utilize any opt in emailing firm, e.g. Neo Email Marketing. It offers money back guarantee.