The deal takes nine months and the firm follows up for two weeks
Professional services buying is slow because it is risky. Somebody is choosing an adviser they will have to defend internally, usually with a budget that belongs to someone else, often alongside two other firms who all look competent from the outside. The decision involves several people, most of whom you will never speak to, and it is frequently postponed for reasons that have nothing to do with you.
Against that, most firms follow up energetically for a fortnight after the proposal and then stop, because chasing feels beneath the professional relationship. The opportunity is not lost to a competitor. It is lost to silence, and six months later the same prospect appoints somebody who happened to be visible in the week the budget was approved.