Serves to organize the distribution (the information on your site) on the users' mailboxes.
Or another - to subscribe (e-mail) user of your website, periodically updated on any information provided by your site.
Such information may be:
- news on the subject of your business,
- news on your site - you can notify your customers about new features of your site,
- news of your company - you can send your customers with information about new services firm, promotions, discounts, etc.
- Update catalog of your products (new arrivals)