This is the 12588th most frequent Turkish word.
ilanından
"From its/her/his/their advertisement."
The word 'ilanından' here refers to 'from the posting' and indicates derivation or source.
Bu iş ilanından etkilenerek başvuru yaptım.
I applied for the job after being impressed by the job posting.
In this sentence, 'ilanından' refers to 'of/from the advertisement' as a source of information.
Gazete ilanından haberdar mısınız?
Are you aware of the newspaper advertisement?
Here, 'ilanından' is used to specify the source of the announcement formed by 'arkadaşının' (friend's).