The rate of a 75 - dollar Amazon card today can vary depending on several factors. Firstly, in the financial market, exchange rates play a crucial role. If there is a significant fluctuation in the currency value against the dollar, it can impact the actual worth of the card when it comes to purchasing power within the Amazon ecosystem.

Secondly, economic conditions also have an influence. During periods of inflation or economic instability, the rate of such a card might change. Retailers, including Amazon, may adjust their pricing strategies in response to these economic factors, which could indirectly affect the relative value of the 75 - dollar card.
Moreover, market competition can't be ignored. Other online shopping platforms or similar offers might be available, forcing Amazon to either maintain or adjust the rate of its cards to remain competitive. This means that the rate of a 75 - dollar Amazon card today is not a static figure but is subject to the complex dynamics of the market.