In most cases it can be assumed that the main official language(s) would be the key driver of performance for any search campaign. However, there are certain complexities that marketers should take into consideration when planning for multilingual campaign expansions.
Key lessons from languages in search
A language with a large number of native speakers will not necessarily translate into high impressions or traffic volume. There can be a variety of factors that influence the amount of times your ad is triggered by a keyword, and even more so how likely somebody is to click it.