Kim Kardashian has joined the 10-figure club for the first time -- she's officially a billionaire ... this according to Forbes, and she can thank her massively successful makeup and shapewear lines for most of it. The magazine estimates KK's net worth has ballooned to a cool billion bucks -- up from around $780 million last they checked in October. The Forbes team says Kim's cosmetics line, KKW Beauty and her SKIMS brand are a huge portion of the increased wealth.