Muzzle, a mac app that silences on-screen notifications, fully embraces this show don't tell mentality on their otherwise minimal landing page. Visitors to the page are greeted with a rapid-fire onslaught of embarrassing notifications in the upper left of the screen. Not only is the animation hilarious, it also manages to compellingly convey the app's usefulness without lengthly descriptions.
If a sales opportunity does not move down the funnel, the sale will not happen and the opportunity should be removed, hence the “leaky” funnel. A leaky funnel is not necessarily bad; as a salesperson, you want to focus on opportunities that are likely to yield results. It is the nature of sales to have to remove an opportunity from your funnel. It does not mean that you will not sell to that account (a positive action by the customer can put them back into the funnel), but for the time being, you should centre your attention on opportunities that remain in the funnel.