As I said in the suggestion thread:

We cannot make people want to clan war, simply put, you can only invest so much money into something before it hits its peak, capping your capital. (Honestly I think 100 dollars for silly clans is already way too much capital to begin with.) The more money you push into something does not mean an equal number of players will join because of it. In reality, the only ones that will benefit from your plan are they ones already clan warring now and perhaps a few more people, but at what gain? They will simply leave deathmatches to play clan wars, it will not gain any new players.

These numbers are fake, but they are an example of what I mean by the term "capping your capital."
Spoiler!