  Decentralized storage networks offer services with intriguing possibilities
to reduce inequalities in an extremely centralized market. The challenge is to
conceive incentives that are fair in regard to the income distribution among
peers. Despite many systems using tokens to incentivize forwarding data, like
Swarm, little is known about the interplay between incentives, storage-, and
network-parameters. This paper aims to help fill this gap by developing
Tit-for-Token (Tit4Tok), a framework to understand fairness. Tit4Tok realizes a
triad of altruism (acts of kindness such as debt forgiveness), reciprocity
(Tit-for-Tat's mirroring cooperation), and monetary rewards as desired in the
free market. Tit4Tok sheds light on incentives across the accounting and
settlement layers. We present a comprehensive exploration of different factors
when incentivized peers share bandwidth in a libp2p-based network, including
uneven distributions emerging when gateways provide data to users outside the
network. We quantified the Income-Fairness with the Gini coefficient, using
multiple model instantiations and diverse approaches for debt cancellation. We
propose regular changes to the gateway neighborhood and show that our shuffling
method improves the Income-Fairness from 0.66 to 0.16. We quantified the
non-negligible cost of tolerating free-riding (altruism). The performance is
evaluated by extensive computer simulations and using an IPFS workload to study
the effects of caching.
