One of the worst pitfalls of productivity is to decide that you're going to execute on something, work on it for some period of time, lose interest, and ultimately quit before you get meaningful results. This happens in obvious cases like writing a book or coding a project, but can also apply to things like learning a new skill or building a new habit.
The danger of this particular pitfall is that besides spending time on something that yields no, or little, results, you've also incurred a huge opportunity cost. The time, focus, and effort spent on that particular campaign could have been spent on something which you would have completed.
There are a lot of possible causes of this, but the biggest might be motivation. Achieving any serious goal requires pushing through some steep challenges, and raw motivation is often the force that can get you through those challenges.
Of particular importance is specific motivation. Some people are generally motivated, eager to grab life by the horns and succeed, but without specific motivation for individual projects, they are doomed to be enthusiastic dabblers. I know, because I've spent lots of time in this category.