Answer:
Colonial boycotts of British goods before the Revolutionary war reduced the profits of the British merchants.
Step-by-step explanation:
There were laws like Townsend Acts, passed in 1767 imposed taxes on tea, glass, paint, lead import. Colonists protested the same saying that these taxes violated their rights as British citizens. They thus started boycotting British goods i.e. stopped buying them. This boycott of British goods led to a series of boycotts which ultimately led to the American revolution.
Boycotts reduced the profits of British merchants. So, they even petitioned Parliament to revoke the Townshend Acts.