A few of the privateers did spectacularly well marauding off Halifax and the West Indies

From the excellent Perilous Fight by Stephen Budiansky, an account of the naval aspects of the War of 1812. Page 287.

American privateering vessels were often beautiful to look at, rakish and distinctive: sharp-lined schooners of two hundred or three hundred tons that could be built in a month and a half, almost everything about them designed for speed over safety or comfort; they had towering masts, light planking that offered little protection against enemy fire or even the normal hazards of wind and weather, almost always relying for their main firepower on a Long Tom, an eighteen- or twenty-four-pounder mounted on a pivot amidships, and almost always relying on cramming a crew of 100 or 150 uncomfortably aboard in order to board and man the prizes they hoped to take. To windward and with enough sea room they could escape from any large warship; with their fleetness and their ability to sail two points closer to the wind than a square-rigged vessel, they could haul off in a direction no frigate or ship of the line could follow. Nipping at the flanks of a convoy, they could dash in and grab a merchant vessel under cover of dark or work in pairs, one leading an escorting frigate off on a chase while the other went in for the kill.

A few of the privateers did spectacularly well marauding off Halifax and the West Indies, and even farther afield. The Yankee out of Bristol, Rhode Island, was the most successful of the war, taking a total of $5 million worth of enemy shipping in its five cruises, crisscrossing the Atlantic as far as Africa and earning its owners and crews $1 million from the sale of the cargoes and vessels it brought back to American ports. The True-Blooded YankeeX, an eighteen-gun brig bought by an American in France, sailed out of Brest on March 1, 1813, and in thirty-seven days captured twenty-seven vessels, took 270 prisoners, held an island off the coast of Ireland for six days, briefly occupied a town in Scotland and burned seven vessels in the harbor, and returned to France with twelve thousand pounds of silk, eighteen bales of Turkey carpets, and two thousand swan skins, among her other booty.