This is an account of a revival in the land of Judah, the southern kingdom, which also had an affect on the surrounding lands as well. What the people of Judah and those surrounding Judah did, was first go out into their own lands and tear down those places that had been used for idol worship. You can see in vs.1 that people banded together and went out together to tear these places down, then they went home to their own properties. The assumption is that at their own properties they then did the same thing.
Revivals must begin with the tearing down of that which inhibits the right and true worship of God. I am sure that there were economic interests involved, but I'm guessing that they were able to pivot to cover the new regime pretty well. As a result of the revival the people of Judah responded in overwhelming fashion, and in a way that surprised the priests and those who reigned in Judah. There were piles and "heaps" of overflow of gifts for the priests. Hezekiah orders that stone chambers be built in order to store the left overs.
This was all a result of the tithes that were being brought in from the people surrounding Jerusalem and in all of Judah and beyond. Without a doubt Hezekiah was an effective leader and was able to motivate the people to not only walk closer with God, but also to take actions on a daily basis that reflected their newfound devotion to God. Tithing is a reflection of a people who love the Lord and are willing to trust that God will provide. Everything Hezekiah did he prospered in.