What is the zara effect?

The quick answer:

Fast fashion = instant 'runway' fashion made accessible for everyone

The longer answer:

Zara is a bridge brand built on the idea of fast fashion. This means that the latest fashion trends move quickly from the runway to its clothing store and have a low-end luxury price tag to match. Zara created the idea of fast fashion and this idea has swept over the retail industry, creating brands like Forever 21, H&M, and Mango. As with all fast fashion stores, the clothes are switched out within a matter of weeks to keep up with the latest trends. Get your goods while they're hot!