I read on here that the red carpet comes from some old book. Some guy was out on an adventure and pissed off his wife, she got her hand maids to roll out a red carpet on the entrance to their home so that the man had no choice but to walk on it. It was symbolic of blood or dripped in blood or some shit and was supposed to be unlucky, or something. The guy had no choice but to walk up the carpet to meet his incredibly pissed off wife.
Amy Henderson, historian emeritus at the National Portrait Gallery, Washington, explains why:
"Agamemnon goes away to fight (in the Trojan Wars) and leaves his wife Clytemnestra at home. He's away for a long time, and they both find significant others. When he comes back he's in love with Cassandra and brings his concubine home with him."
Despite her own infidelity, Clytemnestra is not amused. In her defense, there were mitigating factors: Agamemnon had made a deal with the gods, sacrificing their 15-year-old daughter so he could put the wind in his sails.
"Let all the ground be red / Where those feet pass; and Justice, dark of yore, / Home light him to the hearth he looks not for," says the queen.
"She rolls out the crimson carpet to convince him to walk into his death," says Henderson. Accounts differ, but Clytemnestra either murders Agamemnon in the bath, or he's slain by her lover. She also kills Cassandra. "It's not a pretty story," Henderson adds.
As a conniving early-adopter, Clytemnestra had grim proof of concept that people will follow a red strip of textile.