There is no correlation between the time invested in content and the performance of that content. This is either the best thing about content marketing or the most frustrating. It just depends on how you look at it.
This is an imperfect but helpful idea. Sometimes, content requires a substantial time investment. Benchmark reports, ebooks, data analysis, etc., can’t be useful with significant research and editing. In this case, time invested correlates with quality but not necessarily performance.
Other times, no amount of additional time can turn an uninteresting idea into a compelling one. If the idea isn’t strong or isn’t well framed, that time is better spent on the next piece.