http://www.demon-heart.com/sims4/doris/Logo.jpg The Sims 4 Room Challenge is meant to test your management of social activities without the presence of other Sims. You build an 8 x 8 room on any ...
I'm not sure how long they last, but you only get royalties for X weeks, then they roll off. I started the challenge mostly writing, and got the royalties up to almost 10K a day. But as I switched to mostly painting, the royalties fell off to about 1K by week 9.