As soon as you start sending more emails to people, it’s likely that a small number of people will unsubscribe. But you need to look at the big picture and that is a launch of this kind generates sales and results.
The first 5 emails aren’t ‘salesy’ at all. The first email is a question, which encourages people to get involved and participate. The second email answers their intrigue by giving the top 3 “headaches” you’ve received. The next 3 emails then provide really great information about website development. With a small plug about your website launch at the end.
The open cart week is the most intense. But an email is needed every day to keep up the momentum of the launch and encourage as many people as possible to take action.
If you are worried about people unsubscribing, you could create an unsubscribe link for this campaign only, rather than your original database.