Frankly any client that isn't interested in all of the above is a bad client.
> 'potential clients who are concerned that you are not going to be around for the long term, be able to provide support, offer assurances on security, data integrity etc'
if you are dealing with a large enterprisey potential client, then arguably they may be happy paying you dramatically more money for these assurances. perhaps they would actually be happier paying you more, as then they know that they would be one of your most valued clients.
Trying to cancel a SAAS subscription these days usually leads to seemingly endless (often "cute") emails to try and stop you cancelling, often giving you unwanted trial extensions, or needing to fill in forms requiring mandatory feedback on why you're cancelling or enrolling you in a drip feed of emails extolling the app which you then have to unsubscribe from.
Its got to the point where I've become reluctant to try new apps, knowing that I will be subject to this kind of thing. To me, small SAAS app people, in an attempt to increase conversions and improve retention are becoming increasingly annoying.
SAAS people : if, as a customer, I decide your product is not for me, please make cancelling a 1 step process.
Here is what we do usually. If a client asks to cancel, we will send them a confirmation email saying that account is cancelled but if there is any feedback they can give to help us improve, we will appreciate that. Almost 90% of the time, clients do give feedback when we do this. But thats all. No more second email or a barrage of newsletter emails.
I assume your SaaS offers support, if you're a small team, when they call they will always speak to someone they have spoken to before, if you're a one-man-band, they are speaking to the CEO of the company every time they have a query. They don't have to wait for decisions to filter through, they will get an immediate response.
If they're worried about committing because you might go bust, offer a rolling monthly contract with the option to have 2 month free if they sign up for a year.
You'll be surprised how many go for the year after 2-3 months of paying full price.
Edit: Just to be clear, they aren't nightmare customers - they are within their right to know who they are doing business with. Just don't be ashamed if you're small, turn it around.
That said, this seems pretty rare. I've had casual questions at the end of support conversations (which seem only natural given the expatsoftware.com link in the product site footer), and I sometimes get asked how big the team is on sales calls for large accounts. But never anything so intrusive as you describe.
But if it ever happened, I wouldn't give it a moment's thought. Just mark the mail read and go on leading your life.
So far everybody was happy with the answers, from small to enterprise. Sometimes I wonder if they ask only to see if we (a person) actually call back.