> If User A (who uses the signal app) regularly communicates with User B (who doesn't), then this change might encourage User A to ask User B to join signal. It

> If User A (who uses the signal app) regularly communicates with User B (who doesn't), then this change might encourage User A to ask User B to join signal. It makes a stronger network effect, and will increase viral growth. Conversely, the inconvenience of having multiple messaging apps could cause User A to stop using Signal. Look at what happened with Hangouts when they dropped SMS support.