Standard arguments from the AdS/CFT duality sugggest that the AdS
dual of a planar CFT at zero 't-Hooft coupling is a higher-spin or a tensionless
string theory. We use CFT data to compute one-loop free energy in the AdS side,
and discuss some interesting features of the results. This is a summary
of work with Euihun Joung, Jin-Beom Bae, Wenliang Li and Thomas Basile.