Although you can certainly buy bulk email lists for sale that are high quality and verified to contain voluntary submissions of email addresses, it can often be more effective to your email marketing campaign to build your own email address database from the lists of your own customers and website visitors. Although this can take a while to get to a level which you are comfortable with, it can be done slowly but surely. Some email marketers choose to use a combination of bulk email lists for sale as well as building up their own email lists and email address database, until they have a nice, strong list to use for their campaign.
Certain techniques are known to be more effective for developing an email address database than others. One of the most successful methods is by using a squeeze page. When you include a link to a squeeze page in your email, those who open it are hopefully enticed to click through to your site. When they arrive, they will find the incredible offer that you are promoting in your email. In order to view the details of the offer, or take full advantage of your promotion, they are required to enter in their email address for your email lists and email address database. This is such an effective method because you already know that this customer is interested in what you have to offer and they want to know more about your products and services. While it is possible that they could eventually unsubscribe if they are not completely satisfied with what they find, ideally you have developed something truly practical and useful for them which will keep them returning again and again as a loyal customer.
When a customer enters in their information for your email address database on their own, you have their explicit permission to contact them in the future with other promotions and offers. Having the explicit permission of the recipients on your email lists is one of the basic tenets of email marketing. With nearly everyone in the world suffering from spam overload, people really only want to receive the information that is relevant to them and the information that they are interested in.
So, although you can buy bulk email lists for sale quite easily and this is an effective way to get started, it is in the best practices of email marketing in general to develop your own email address database over time, filled with the addresses of truly interested customers.