Reasoning
Multiple credible sources (CRM.org, TechRadar, The Digital Project Manager, PCMag) consistently indicate a free starting plan with 0 USD per user per month. PCMag explicitly notes 0 pricing for up to 12 users, reinforcing the existence of a free tier. The overall pattern across sources supports a free starting price, while other figures (e.g., 15, 99) refer to higher-paid tiers and are less representative of the starting price.