MailerSend vs. Customer.io
Side-by-side across both vendors’ full G2 portfolios — reviews, ratings and category coverage aggregated to the company, not a single product.
| Metric | MailerSend | Customer.io |
|---|---|---|
| Avg. rating | 4.1 | 4.4 |
| Total reviews | 46 | 990 |
| Review growth (QoQ) | — | +7.1% |
| Products on G2 | 1 | 1 |
| Categories covered | 1 | 7 |
| Best category rank | #52 in Transactional Email | #1 in Transactional Email |
| Small Business | 95.6% | 59.3% |
| Mid-Market | 4.4% | 37.4% |
| Enterprise | 0.0% | 3.2% |