Imvu is not good, you can often get easily banned, what they called disabled, many have complained of being on there some years, having spent thousands of dollars and suddenly one day they can not access their account.
Another worrying thing is the amount of accounts that get hacked, so a lot of them claim on the forums. If you complain to much you get banned and later disabled.
Finally you have no realy safety on there, so despite the minimum age being of 13, anyone young can get access to the site. There is often naked graphic p-o-r-n images too, which makes it very unsettling given the fact there are young teens on the site. IMVU removes the naked images of men, but often avoids and leaves those of the women, for whatever reason, who knows.
If I had to rate the site over all, give it 1 out of 10, better ringing them for someone decent to answer you, but then having said that, just given the run around as you are told to take out a ticket on the site, thus one can wait days or weeks, if they respond to you at all.
As for the offers to get credits, most are a con, surveys all about getting your details off you, to bug you constantly, a serious privacy risk, especially for kids, which it appeals a lot to. And not only that, when you gone through them, often then say sorry at this time not qualified etc. We then have those free things one downloads, and these are often full of spyware or virus.
For a company making so called millions of dollars now, to not be accountable to even paying customers is truly shocking to say the least.