[clairity]

i believe that's the reasoning for why many systems have devolved to boolean choices rather than multi-tier (distortions in voting cause mispresentations of the customer population's sentiments).

but boolean choices are really 3-tier systems where it's assumed that only the extremely statisfied or dissatisfied customer will vote (up or down), and the lukewarm/indifferent customer is assumed not to vote. however, that assumption very likely misrepresents the sentiments of the (majority) non-voters and thus the population as a whole.

you might address this by moving to a 3-tier system: (1) unsatisfied/bad, (2) acceptable/fine, (3) exceeded expectations/great to more accurately differentiate the non-voting/indifferent customers, but non-voters would have no incentive to suddenly voice their opinions and make the system more accurate.

you might be able to counteract that impulse by incentivizing customers to vote on every product/service delivery event (like earning points for future discounts) to lower response bias. you could also do a separate study to see how the voter/non-voter population differ, and adjust the boolean ratings accordingly.

in any case, rating systems are tricky.