Needless to say how important it is to segment your list before you try to send your newsletter. The truth is that segmenting your list will not bring you more opens or clicks. When you want to talk about football, either you send your message to all your recipients or to half of them, your open or click through rate will most probably come from your male audience. But if you have just used all your mailing list for this campaign, women will have probably been annoyed.
So segmenting your list does not mean your message will have more impact or a better performance. The impact will be the same. Segmentation will help you be less annoying to your recipients that are not interested about your message. The ones interested are going to open it either way. And the rest will be happier when they realize that what they receive from you really concerns them. This will definitely bring engagement. So along the way, what you earn is a good impact of you brand and your mailings: they are not annoying, and most probably a part of your recipients find it interesting. What more should you need?
Moreover, what you should have in mind is that if your list has grown big, your recipients have even more different interests. So as your target audience change, you have to find new ways of communicating with them, and that means you have to target your message. Along the way, you will change your marketing strategy according to the profile of your recipients.