The the early years of the 1960s Batman Comics were nearly cancelled due to dwindling sales. Young upstart Marvel Comics was literally cleaning the clocks of DC Comics with comics that had zip, hip and trippy dialogue and situations that appealed to an older demographic of fans, many in college. They hitched on to the Pop Art Movement and became the subject of articles in magazines like Time and Rolling Stone.
Meanwhile, Batman's adventures kept getting more and more ridiculous-- with Batman changing into a giant gorilla or being plagued by Bat Mite-- Julie Schwartz and a new team of writers and artists were brought in around 1964 to save the title and they did so by taking Batman back to his more mysterious detective roots.
Then the 1966 Batman TV Series hit and suddenly Batman was a national sensation, and the comics of the time attempted to capture some of the camp-- so it was back to silliness for a while.
This particular cover, by DC Comics President Carmine Infantino is particularly interesting. Remember the idea of the cover is to sell the book-- so in this case we see Batman has fallen on hard times-- the Batmobile is sold, Robin's costume is sold-- Alfred and Robin are broken up in the foreground watching this happen and Batman is now about to auction off his suit-- but he's still wearing it.
The art seems to indicate that he's going to pull it off for the high bidder-- and here's hoping the Bat-undies are not included in the sale. Nobody wants to see the bat junk.