We use ActiveCampaign for marketing smart automation and also consult with other companies on selecting marketing automation tools. ActiveCampaign is a very powerful tool for small businesses looking for a rich feature-set at an affordable price.
Since it has so many options, a beginner might be overwhelmed by the choices available. This is hard to avoid when offering so much flexibility, but still, a new user would be well-served to watch some tutorials and have a clear idea about the workflow they want to get started.
There is a point at which your list will outgrow the service (hopefully!) and you might want to think about switching to a service whose CRM and landing page functionality is more robust.
Compared to options like MailChimp and Constant Contact, ActiveCampaign offers a much more robust and granular delivery feature set. Compared to more robust options like Infusionsoft or HubSpot, it offers much of the same functionality for a fraction of the cost. Once your list grows into the thousands, you'll want to consider Infusionsoft or HubSpot for their better CRM features, but if your list is smaller and you want to get aggressive about growing it, this is the tool for you.
For the small business who is just getting started or has a list smaller than 2,500 contacts, ActiveCampaign is a leader in smart communication. Compared with free (or cheap) alternatives like MailChimp or Constant Contact, the feature set provides a lot more value. The one real caveat here is that you have to really want to use the features. For someone who is happy to just send out their monthly newsletter, this might be more than you need.