The phrase "are incredibly effective at" is correct and usable in written English.
You can use it to describe the high level of effectiveness of a person, method, or tool in achieving a specific goal or task.
Example: "The new marketing strategies are incredibly effective at increasing customer engagement."
Alternatives: "are highly successful in" or "are exceptionally good at".
Marketers are incredibly effective at persuading consumers to do and buy things.
Friedman, who was one of the most brilliant thinkers of this past century (and my neighbor in San Francisco, albeit in a much nicer apartment), was at the forefront of arguments that markets are incredibly effective at allocating scarce resources.
Murphy USA's stores have smaller footprints relative to other gas stations' stores, and they are "incredibly effective at selling tobacco, an item generally more expensive than most other convenience store items," Fredricksen said.
Bed nets treated with long-lasting insecticide are incredibly effective at protecting people from contracting malaria.
Opponents of clean elections are incredibly effective at gaming the system so that their interests are protected despite the will of the people.
But, they are incredibly effective at burning fat and building cardiovascular strength...so keep that in mind when you remember how much you despise burpees.
While teachers can be incredibly effective at prevention and spotting early symptoms, they cannot be doctors.
And conservatives have been incredibly effective at making that the debate.
Her spokesman, Kevin Harris, said the mayor had been "incredibly effective" at moving her agenda through the council.
Enlargement has been incredibly effective at promoting free speech in countries that for years fell under the curse of Soviet totalitarianism.
"Even though we lost the case initially, it was incredibly effective at spurring the Environmental Protection Agency to action," Michele Hirshman, Spitzer's deputy, recalls.
