The role of bubbles in the transportation of hydrophobic particles to a froth phase in flotation is well established. However, analysis of available data reveals that the bubbles are important most of all because they are the primary means of transportation of flotation agents to the points of bubble-to-particle attachment. The common view is that bubbles attach and lift hydrophobic particles to a froth layer. The thermodynamic analysis presented in this paper also leads to the conclusion that also the particles which become hydrophobic during the particle-bubble collision and attachment can be captivated by bubbles.