Big sites like Amazon will show high in the PPC results because they have huge budgets and can afford to pay for the placement.
They also have enough money to hire dedicated PPC agencies to manage their campaigns.
Often, smaller local businesses will not show as highly because they lack the budget and the expertise to optimize their campaigns.
In pay-per-click, the top spots go to the companies that have done the best job of optimizing their campaigns, and that are willing to pay the most per click. If a local company manages to do a better job of targeting their campaign and has the budget to pay for the clicks, they can still do very well.