Photo: Salesforce chief Marc Benioff. Photo by Bloomberg.Just in time for the holidays, we have a possible big enterprise software merger. Salesforce’s interest in buying Slack, first reported , shouldn’t come as a surprise to anyone. We could be a bidder for the workplace messaging service last January, along with several other companies (which raises the possibility of other bidders emerging).Slack is enormously popular among its users, but like a lot of popular products, it belongs to a smaller company that doesn’t have the scale to compete with bigger rivals. And its growth has been...…Photo: Salesforce chief Marc Benioff. Photo by Bloomberg.Just in time for the holidays, we have a possible big enterprise software merger. Salesforce’s interest in buying Slack, first reported , shouldn’t come as a surprise to anyone. We could be a bidder for the workplace messaging service last January, along with several other companies (which raises the possibility of other bidders emerging).Slack is enormously popular among its users, but like a lot of popular products, it belongs to a smaller company that doesn’t have the scale to compete with bigger rivals. And its growth has been...WW…