vikasa wrote:....so I am willing to trust this company with my (potentially lots of) money but not with my real email address? .. Surely my email address is not more valuable than my money, is it?
Your money certainly is more valuable than your email addr, but that does not mean that the latter is worthless. I
do trust the bank with my money, but not with my email addr, because the bank (and everyone else in the world) recognise that stealing/losing your money would be a very serious crime or at least a major fail (and headline news), for which you would almost cetainly be re-imbursed (unless the bank actually go bankrupt at that moment), but OTOH many people (including maybe the bank's marketing dept) would regard the misuse or sale of your email addr as "just one of those things", to be shrugged off, and there would certainly be no sort of re-imbursement for it (how could there be? the djinne is out of the bottle).
In fact the marketing dept would not even regard spamming you as misuse of your address - these people really believe they are "enriching" your life and doing you a favour.
The bank is therefore more likely to misuse your email address than your money, because they are more likely to get away with doing so.