Translation:The cost of advertisement is very great.
This is the fourth sentence in a row that I have been told that my native English is not correct. This is frustrating.
"Advertisement" needs an article to be correct. "Advertising" or "advertisements" would not.
This is not a surprise to me. Duo vietnamese program needs a lot of improvements.
What I meant was to replace advertisement with advertising, that way it actually makes the sentence grammatically correct.