- Be Scientific: For someone who has an established list with at least a few thousand readers, why not try an experiment? Split your list in two and try a different promotion for each one. For example, for 1/2 the list, offer 50% the first hour’s fee. For the other half, try offering a $100 credit if they sign up for 5 hours (this promotion will change for different types of products and services). Then, study the effectiveness of each promotion — either in clicks or in new sales. Most importantly, try new variations at another time based on what you learned.

- Send Tuesday through Thursday morning: we mentioned this in our beginner’s guide, but it is something that would benefit a more established newsletter. In most cases, newsletters are best sent in the mornings on weekdays that are not Monday or Friday. With that said, consider your product or service — and consider whether it would be better sent some other time. For example, camping products might sell better on a Friday afternoon as that’s when people are thinking about camping.

- Watch your Words: Internet Service Providers and users use many different types of software to determine whether an email is to be considered Spam or not. Some criteria are technical — do you send your newsletter from a server that sends other suspect email, for example? Some are content-based, mentioning the word “viagra” may make your message more likely to be blocked.  A full list of one software package’s tests are here. Even if your email legitimately uses content that may cause concern for anti-spam software, your email could still be blocked. Considered avoiding or using less words or phrases of this type.

- Customize Your List: With a larger list, consider subdividing the list into different types of users (you can do this with Constant Contact or with other providers). You can go in many different directions with this: You can split your users into different timezones  which will allow you to send the email at 9am local time, no matter the time zone. You can split your list into different interest groups, promote a golfing product to golfers, and a gardening product to gardeners. Be careful about splitting your lists too much, no need to have lists of 10 or 15 people — it won’t be worth the time invested in doing this.