Best Answer: There are plenty of ways to get promocredits provided by IMVU. Spin Free is always good http://www.imvu.com/catalog/web_spinfree. but it's never a sure thing. By visiting the New Products page of the IMVU catalogue http://www.imvu.com/catalog/products_new. once every day, you'll automatically get 50 promocreds each time. Competing in the Daily Oufit Challenge can earn you a handsome number of credits if your outfit is good enough.
Refering people to IMVU is a good way to get promocreds if you have a website or a myspace account that is has pretty good traffic. More information about that is in the Power Earners Program http://www.imvu.com/catalog/web_info.php.
For more ideas, check out IMVU's FAQ page http://www.imvu.com/catalog/web_info.php?section=Info&topic=usagerewards&nav_section=credits&nav_subsection=earn
Getting real, money-value credits though, is more challenging.
Unless you buy them, there are very few ways to get them. I'll let you in on my method, though ;)
I use MetaRL - it has helped me out tremendously. You play games, enter contests and get referals, and they give you points for everything you do. Then you can cash in those points for credits you can use on IMVU, SecondLife, or Entropia. MetaRL pays IMVU for the credits; so it's not a cheat, but you still get your credits for free. You can get the "Guest_" removed from your avi name for free when you have enough points. They'll even give you items from your wishlist in one of their daily contests! I love it! Isn't free wonderful =)