Having a subscription form on your website, offering something unique to your readers can be a good way to start building your email list. Once you have a good number of people in your database, you can send out different offers.
Please keep in mind that overdoing it can lead to negative effects: for instance, you are sending out multiple emails daily with same offers can force your users to unsubscribe or mark you as spam. Certainly you don’t want this to happen, so find the golden way to do it properly.