We have existing business relationships with a small selection of suppliers who are reliable, cost-effective and deliver on time. Until they foul something up badly, or we need something they can't provide I don't go looking.
New suppliers are chosen based upon recommendations from people I know and trust. While your (correctly targetted and succinct) sales literature may make me aware of you as a contender, it (and you) will not be a major deciding factor.
Don't chase me. Ever. Don't make follow-up calls. If I'm interested or want further info, I will contact you.
NEVER chase the headmaster if I'm not available - you will lose all future and any current sales.
I am never not busy.
If I say I'm busy, don't stay on the phone for long.
If I say why I'm busy, it generally means that if you had any clue, you would realise now is a Bad Time and apologise and hand up immediately