During this period, Kiss merchandise became a substantial source of income for the group. Some of the products released included a pair of comic books issued by Marvel (the first contained ink mixed with actual blood donated by the group), a pinball machine, dolls, "Kiss Your Face Makeup" kits, Halloween masks, board games, lunch boxes, trading cards and many other pieces of memorabilia. Membership in the Kiss Army, the band's fan club, was in the six figures. Between 1977 and 1979, worldwide merchandise sales (in-store and on tour) reached an estimated $100 million.