Vonage to Vonage Calls are always free with your monthly calling plan. Call domestically. Call internationally. It doesn't matter. If the person you are calling is a Vonage customer you can talk as long as you like for free.
If you buy two Vonage lines and give one to someone, you can stay in touch for free. Vonage to Vonage Calls are always free, so they never count towards any Vonage rated monthly phone plan.
It makes great sense for you to sign up people you know. If you use our Refer-A-Friend program, you'll get two free month's of Vonage service and so will the people you refer.