One of your most valuable assets is people who won’t buy from you–today. They are the majority of your prospects. But if your business is typical, and I hope it isn’t, the majority of your sales leads slip away and never give you their business. Drip marketing is the way to win them.

In two separate studies, trade magazine publishers Cahners and Penton discovered that around half of the people who inquire about an advertisement they see in a trade magazine place an order within 24 months.

So what should you do with these buyers who aren’t ready to buy? What can you do today to get their business tomorrow? Well, here are two things you shouldn’t do.

1. Don’t pass all sales leads to sales.

Salespeople want qualified leads, and a qualified lead, in their view, is someone who is ready to buy real soon, not 12 months from now. Most salespeople lack the resources and patience to follow up with every sales lead. They concentrate instead on immediate opportunities.

2. Don’t wait until the lead is ready.

A lead who isn’t ready to buy for a number of months needs to hear from you between now and then. Otherwise they will forget you. Or a competitor will come along during the interval and grab your lead’s attention, and purchase order.

The most effective way to convert long-term leads into sales is drip marketing. Drip marketing is the process of sending repeated, relevant messages to your prospects until they are ready to buy. Drip marketing is like drip irrigation, where farmers and gardeners apply small amounts of water to plants over long periods of time.

Drip marketing is usually automated, and relies heavily on email marketing letters and newsletters sent to opt-in subscribers.

Drip marketing is effective because it helps you stay in touch with the people who are not ready for a sales call today. Drip marketing keeps your brand in the top of their mind. Drip marketing ensures that you follow up with every single sales lead, and only hand over to your salespeople the leads who are primed and ready to discuss a purchase.

You tend to forget people who don’t stay in touch. But you tend to remember people who phone you, email you or write to you over time. That’s the beauty of drip marketing. It helps you show a sustained interest in your prospects until they’re ready to buy.