My wife and I are pitching the services of (a still very) small startup (with a big idea) to some pretty big corporations. Big corporations are busy and overloaded with requests of small companies to talk to them. It is fine to play hard to get, but if you accept a meeting/call, don’t cancel at the exact minute the meeting is about to start unless there is some medical emergency.
The world is small and memory is surprisingly good. Personally, I had a few cases of poor interactions with people as a presentation designer (not paying agreed invoices for example) with people that re-appeared 5-10 years later with a request for another presentation (‘‘Hey, I am doing my own startup now and got a meeting with these investors next week, can you help?”), or were the subject of a reference call (‘Do you think I can trust this person with my investment?’)
Basic human interaction hygiene.