The phrase "advertisements were placed" is correct and usable in written English.
You can use it when discussing the action of putting advertisements in specific locations or platforms, often in a marketing or business context.
Example: "After careful consideration, advertisements were placed in various online and print media to reach a wider audience."
Alternatives: "ads were positioned" or "commercials were set up".
Public service advertisements were placed on radio and television.
The advertisements were placed by the Chinese Communist Party's central organization department and the State-Owned Assets Supervision and Administration Commission, the high-level government body that oversees the operations of China's 129 biggest state-controlled corporations.
Political issue advertisements may be found here and include presumably World War II era cartoons of the "Axis Ape". Some Public Service-type advertisements were placed under the sponsor's usual category, if the sponsor's name was an obvious part of the advertisement.
Those advertisements were placed on Craigslist for Hampton Inn, Best Western and Residence Inn properties, respectively.
Advertisements were placed describing "dangerous and rigorous" trials which would form the basis of the country's first bobsleigh team.
Advertisements were placed in local newspapers such as the Daily Chronicle and The Journal and Courant to solicit donations for the kitchen.
The overhead bins have had a slightly faster uptake than the seatbacks at Ryanair, with advertisements being placed by companies like the Dutch bank ING Red Bulll, the energy drink; and Meteor Mobile Communications, an Irish cellphone operator.
Sections of American business and labor have expressed chagrin about Indian trade and investment policies — their unhappiness has been evident in letters to and from congressional members, at hearings on the Hill, and in advertisements being placed in advance of the prime minister's visit.
The court ordered advertisements be placed in two national newspapers as well as papers on the Channel Islands, which Savile used to visit.
Only then would government advertisements be placed in these papers to save them from bankruptcy.
In a world where advertisements are placed literally everywhere, it can be hard to get your company noticed by your ideal clients.
