AWeber – It’s often the case that you’ll let people try your service for free or for a limited time. Of course, as a good marketer, you’ll ask for their email in exchange for the free trial membership. Once you’ve got that email, you’ll need an autoresponder like AWeber to keep in contact with them. AWeber makes it easy to email contacts en masse and also tracks analytics about individual email campaigns. If AWeber doesn’t suit your fancy, have a look at competing tools such as MailChimp and GetResponse. Any of these will work well and keep your prospects engaged.