Ideal for professional marketers, entrepreneurs, and small to medium-sized businesses, ActiveCampaign is a feature-packed e-mail marketing platform that gives you a bang for your buck. From SMS marketing to invoice creation and even a CRM, the ActiveCampaign team has added loads of bonus features useful for expanding businesses looking to stay in touch with their customer base. All in all, adopting ActiveCampaign as your marketing automation service affords your company a lot more flexibility and room for growth, though it does require a heavier time investment to learn at the beginning.