The Crusades created a demand for Eastern goods. The wars created a need for continuing supplies, which increased their manufacturing.
Also, the Crusades failed to rescue the Holy Land permanently from the Muslims. Pope Urban called on Western Christians to recapture the Holy Land from Muslim control, but they failed after eight major Crusade expeditions.
Finally, the Crusades brought about the breakdown of the medieval way of life. After them, there was an increased interest in travel and learning, which many historians believe gave birth to the Renaissance.