As someone at in an agency still working in a "waterfall style that was popular in the 90s", how do we convince clients with a fixed budget and a list of "must haves" to go agile? We have PMs with agile experience, all the developers are onboard, but when every other agency is promising to deliver what the client needs for a fixed cost, why would they take the risk?

We've had some small successes starting agile projects with existing clients who trust us, but articles like this make it seem like we're incompetent for even engaging in a waterfall project in 2016. When you're pitching for new work with a client who doesn't know the difference between waterfall and agile, one seems like a promise and the other seems like a risk. As software engineers, we know the opposite is true, but why should they trust us?