If you're inviting readers to download an ebook, for example, and you have a picture of the ebook included in the email, don't just hyperlink the text next to the image telling people to "download it here." Hyperlink the ebook's picture, too. People are drawn to images much more commonly than text, and you want to give your email subscribers as many options to get your ebook as you can.
Drip offers a very small forever free plan, along with a two-week free trial for the Basic and Pro membership levels. If you choose to continue service after those two weeks, then your card will be charged. There is a 30-day refund window from when you start your service, but it’s up to the discretion of Drip whether you will receive a full refund.