My experience with ActBlue over the years is primarily in the field of digital/fundraising. I particularly found it helpful for quickly creating landing pages/forms when we needed to turn around content quickly. They are also very good at developing content that is mobile-friendly, which greatly increases conversion rates. They also provide A/B tools which are great for testing emails. Review collected by and hosted on G2.com.
There were a few times when ActBlue customer service/communication could have been better over the years, particularly when the service was down or donors had trouble with their contributions (and I'd need ActBlue to clear up the confusion). I do believe that the organizations has been doing a better job of improving support communication (and pledging to resolve problems on their end) over the years. Review collected by and hosted on G2.com.