There is one persistent fake credit reseller who uses a number of techniques to get IMVU users to buy credits from him. This reseller has been spamming IMVU in many ways for a long time, and many users have lost money and never received credits.
Always be suspicious of very low prices and always check the authorized resellers list.
The IMVU reseller group scam consists of sending invite messages to users randomly. New users in particular are prone to join, being excited to get some action and being "wanted".