Budget pressure: ActiveCampaign starts at $15/mo. If that's too steep, Mailchimp, GetResponse, HubSpot offer free tiers. The cheapest option isn't always the best — but neither is overpaying.
Feature mismatch: ActiveCampaign's strengths are most powerful automation and excellent crm integration. If you need something it doesn't do well — steeper learning curve — one of these alternatives fills that gap.
Scale: What works at 1,000 subscribers may not work at 50,000. Re-evaluate your platform as your list grows — pricing and feature needs change faster than most people plan for.