spray and pray
v. phr.— «It’s a strategic buy.…We have not tried to spray and pray. Because we don’t have a large budget, we put our money in the one place where we know we’ll have a large audience.» —“Radio Spot Snags Addy Best of Show” by David Knorr Grand Rapids Business Journal (Michigan) Feb. 29, 1988. (source: Double-Tongued Dictionary)