The people of the capital were superficial, so they wanted to see a love story between someone. When Katniss and Peeta were kissing, it made them want to see more, so sponsors came out and they decided send things to help them survive so that they could see more. In a way both of them represent hope and superficialness.
After Katniss kissed Peeta, Haymitch sent the silver parachute as a way of saying, "one kiss equals one sponsor", because that's what the viewers in the Capital want to see.
