From Social Patterns
User sends an invitation to a friend or group of friends to have them join in a site experience.
- Use when the user experience is enhanced by having a network of connections.
- Use when growth of the service is dependent on friends of friends.
- Use when you want to supplement traditional user acquisition with user based referrals.
- Use when a user has participated in the site enough to have formed an opinion of the value, to then recommend it to a friend.
- Don’t use right after registration when the user hasn’t actually used the site. When presenting the option to invite others, do so after enough interaction with your site that the user actually has something to refer.
- [does the above point become invalid when the use of the site is actually dependent on bringing a network of people with you into the site?]
- Use an in-context email form.
- Provide the user with messaging that showcases the benefits of joining the service.
- Make the pre-filled content editable and allow the user the ability to personalize the invitation.
- Allow the user to invite others via access to their address books.
- Provide a mechanism that allows the user to send a copy of the message to themselves.
- Provide a mechanism to bring contacts and email addresses over from other social services. Use a standard accepted technology like OAuth and OpenID rather than the password anti-pattern (see The Password Anti-Pattern).
- Don’t force a user to invite others to the site before they have had a chance to try out the features.
- Don’t spam a user’s address book or contact list from other sites.