The quantum states of the supertube are counted by directly quantizing the
linearized Born-Infeld action near the round tube. The result is an entropy S=2Ο2(QD0βQF1ββJ)β, in accord with conjectures in the
literature. As a result, supertubes may be the generic D0-F1 bound state. Our
approach also shows directly that supertubes are marginal bound states with a
discrete spectrum. We also discuss the relation to recent suggestions of Mathur
et al involving three-charge black holes.Comment: 15 pages, v2: reference corrected; v3: few corrections and explicit
derivation of a relation are added to appendix