To efficiently utilize ultra-short range wireless technologies providing extreme data rates at the air interface, the concept of information shower (IS) has been proposed to complement typical small cell deployments. Although the concept was introduced several years ago, the benefits of ISs is still an open question. We propose an analytical framework for performance evaluation of ISs operating in the terahertz (THz) frequency band. Taking into account different THz bandwidth allocations resulting in different IS coverages and capacities and assuming applications capable of data prefetching, we estimate both user- and network-centric metrics as a function of input parameters including mobility of users. Our study reveals that initiating heavy traffic sessions upon entering THz ISs allows to offload up to 95% of traffic from long-range networks even for low IS sizes and high user densities as the THz IS data rates efficiently compensates for large inter-IS visit times. Such massive offloading also results in considerable improvements in mobile terminal energy efficiency as the fraction of time the radio interfaces have to be active drastically decreases.