  We simulate the process of possible interactions between a set of competitive
services and a set of portals that provide online rating for these services. We
argue that to have a profitable business, these portals are forced to have
subscribed services that are rated by the portals. To satisfy the subscribing
services, we make the assumption that the portals improve the rating of a given
service by one unit per transaction that involves payment.
  In this study we follow the "what-if" methodology, analysing strategies that
a service may choose from to select the best portal for it to subscribe to, and
strategies for a portal to accept the subscription such that its reputation
loss, in terms of the integrity of its ratings, is minimised. We observe that
the behaviour of the simulated agents in accordance to our model is quite
natural from the real-would perspective. One conclusion from the simulations is
that under reasonable conditions, if most of the services and rating portals in
a given industry do not accept a subscription policy similar to the one
indicated above, they will lose, respectively, their ratings and reputations,
and, moreover the rating portals will have problems in making a profit. Our
prediction is that the modern portal-rating based economy sector will
eventually evolve into a subscription process similar to the one we suggest in
this study, as an alternative to a business model based purely on advertising.

Other Condensed Matter