All of us would love to save money on things we need. You can always use a price tracker to keep up with prices on Amazon and other online stores. Would you like to add such a feature to your own store? The WooCommerce Price History / Price Alert Notifications extension can help. This plugin puts price changes on a graph and lets your customers sign up for price alerts.
This script can show the current, highest, lowest, and average price for each product. Your visitors can see the last price changes and enter the lowest price they want to get a notification on. They can also remove their email with a simple click.
Webmasters have the option to export email addresses as a CSV file. This is a paid plugin by AA-Team. You can find out more about it here.