Much like Hansel and Gretel, your leads have left a trail of breadcrumbs. Fortunately for you, birds don't favor digital breadcrumbs, nor have we seen any witches in the woods lately.

In this series of blog posts, we'll expose 10 places your missing leads might be hiding and show you how to bring them back into your sales funnel.

Have you ever shopped with your favorite online retailer, put something in your cart and never completed the purchase?

If yes, turns out you're not alone. Research shows that although abandoned carts lost almost 4 trillion dollars, 63 percent of that total may be recoverable via the use of savvy email marketing.

Why do shoppers abandon purchases? According to Moz, an authority on inbound marketing and SEO, the top reasons include:

Unexpectedly high shipping costs
Not yet ready to make the purchase
Comparing prices between competitors
Price was too high
It costs far less to retain a customer than it does to attract a new one, and it is easier to convince a previous purchaser to press "buy now" again than it is to convert someone who has never bought from you before. Your past purchasers are already familiar with you, your products, and your services. And they were receptive to your messaging in the past. This means the hardest part of your job-earning someone's trust-is already done.

Encouraging a past customer to buy again, often called remarketing, has impressive success rates. According to Salescycle, remarketing email open rates average 57 percent and a 30 percent conversion rate (versus a typical 21 percent open rate and 3 percent conversion rate).

All you need to do now is to do a little experimentation to figure out the best incentive to bring those customers back to purchase again.