Promotional bookmark for the Steve Allen and Morey Amsterdam television programs which were seen on WNBT-TV, New York. The bookmark carried a promotion for Allen on one side and Amsterdam on the other. The promotion was shared with Pocket Books and Cardinal Books, who were publishers of paperback books.
Date
Most likely May 1950, as that was the time when Amsterdam was hosting NBC's late-night time slot. No later than 1954, as the station was no longer known as WNBT after that date.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.