Copé brandished the book, which features various characters - a businessman, a teacher, an old lady - stripping off and running to the beach, on a TV programme on Sunday, claiming that it was recommended for use in primary schools.
Since then it has shot to number two on Amazon's French site and 1,287 copies, at 15 euros a piece, had been ordered on the internet or in bookshops by Wednesday, according to publishers Rouergue.
The company, which only sold 1,500 copies when the book appeared in 2011, will order a reprint as soon as stocks are exhausted.
Copé on Thursday hit back at Socialist ministers who accused him of book-burning tendencies, accusing them of "hate-filled language".
His comments come amid a row over a government project to combat gender stereotypes in schools.
Ministers say that the book is not recommended in the programme but mentioned by the Grenoble education authority at the suggestion of a local NGO.
The right-wing Printemps français movement, which arose from last year's campaign against gay marriage, confirmed this week that it was targeting libraries to press them to withdraw books it claims propagate "gender theory".
The group's leader, Béatrice Bourges, said that members were phoning and emailing libraries "all over the place" after Culture Minister Aurélie Filippetti denounced pressure on libraries from "extremist movements".
Filippetti said that such groups "put pressure on the personnel, go through the shelves with a particular obsession for the children's section and demand the withdrawal of any books not corresponding to the moral they claim to incarnate".
The right-wing Le Figaro newspaper quoted several libraries as saying that the campaign has been small scale and found no cases of people going to libraries.
"Maybe that's going on but I don't know about it," Bourges said.