One of the questions in Cagan's opportunity assessment is why now. What is it asking a team to establish?

The principle — an idea can be correct and still be attempted at the wrong moment.

Why the key is correct — Cagan lists Why now? (market window) as one of the assessment's questions. It asks what has changed — in technology, regulation, cost or behaviour — that makes this the moment, and it is answerable before any work begins.

Why the others are wrong — a campaign date is scheduling that follows the decision rather than informing it. A quiet competitive field can mean the window is shut rather than open. And market size is its own question in the same list, which is why a large market and a closed window can coexist.

Remember this — why now asks what changed, and a good idea with no answer is usually early.

Sources — Marty Cagan on assessing product opportunities, Silicon Valley Product Group.