You want permission to avoid annoying visitors who get email which they did not desire or request. Moreover in many countries there are laws concerning unwarranted emails and if you are not using opt-ins you may be violating these laws.
Another option which is yet not very common but can protect you from being accused of spamming is the use of double opt-ins. This feature confirms from the person whether his or her email address should be placed in the contact list or not email list through an initial email response. 2) Apart from using promotions, offer something extra. After being granted permission for the opt-in, start marketing immediately before people put you in their spam folder. The ability to send quality email is something that requires skill.
Avoid becoming merely commercial by simply doing sales, because in doing so, your emails might be ignored even before they are read. By including quality information and helpful tips, your subscribers will have a reason to open up your emails. If you are successful in establishing good relationships, a comfort level will be built up automatically and readers will be more likely to look at additional products or services you are offering.