You are asked to analyze trial-to-paid conversion using AlphaSense-style product data. Write a PostgreSQL query that returns each signup month, the number of trial users in that month, how many converted to paid within 30 days, and the resulting conversion rate. Only include months with at least 3 trial users.
| Column | Type | Description |
|---|---|---|
| user_idPK | INT | Primary key for each user |
| signup_date | DATE | Date the user created an account |
| segment | VARCHAR(50) | User segment such as enterprise, team, or individual |
| country | VARCHAR(50) | Country of the user |
| Column | Type | Description |
|---|---|---|
| subscription_idPK | INT | Primary key for each subscription event |
| user_id | INT | Foreign key to users.user_id |
| start_date | DATE | Subscription start date |
| plan_type | VARCHAR(50) | Plan name, including trial and paid plans |
| status | VARCHAR(20) | Subscription status |