Could it be that the business requirement for the ranking system is actually that users be given the illusion of participating in a social site? because ultimat

Could it be that the business requirement for the ranking system is actually that users be given the illusion of participating in a social site? because ultimately the rankings have very little impact on overall sales? While over there, the "Users who bought X also bought Y" feature has a very strong impact on sales, so the engineers spend all of their time tweaking its algorithm?