Write the next sentence in the following story.

How to collect email addresses 
Create a sign-up sheet. 
If you have an actual storefront, place an e-mail sign-up sheet near the register. Point it out to each customer who makes a purchase.
Similarly, you can instruct your cashiers to ask each customer who approaches the register for an e-mail address. Make sure that your cashiers tell your customers that providing an e-mail address is only optional while explaining the benefits of doing so.