Reopen registration exclusively to individuals who have received invitation codes from previous users of your service (excluding spammers). New registrants will have to wait a while before receiving invitation codes to distribute with their connections. 1-3 months, or more if the account is questionable or suspicious. This gives spammers enough time to lose patience.
Reopen registration exclusively to individuals who have received invitation codes from previous users of your service (excluding spammers). New registrants will have to wait a while before receiving invitation codes to distribute with their connections. 1-3 months, or more if the account is questionable or suspicious. This gives spammers enough time to lose patience.