I suppose many are familiar with the situation, when you receive a cold call from someone very enthusiastic to recommend you a "great financial offer" and starts talking endless marketese, and if I ask a few direct questions it is revealed that they call from a bank (usually a small and not well-known one) and they just want me to open an account, take a loan, or subscribe for a credit card.
However, lately it seems that they have at least some information about my financial status. A couple years ago, when I wasn't standing well financially, the offers were usually about loans and credit cards. Now that I have a relatively good job and also some savings, the offers are about making a savings account, investing, or stock trade.
How do they do it?
I'm generally self-conscious about my privacy, I don't give personal information to strangers, don't say anything other to telemarketers than "sorry, I'm not interested", and I have only one main bank account with any significant activity for now at a fairly large and well-known bank. Should I suspect my bank that they give away information about my account to other banks?
They might take a look at my credit rating, I guess they can obtain that information legally, but I never ever had a credit card and never took a loan, so this shouldn't provide them with any information.
While I try to take good care of my privacy, I know that a detective could gather information about where and how I live, where do I work, how much do I spend, etc, but I'm sure that banking telemarketers call a lot of people and don't spend huge amounts of time and money in researching individuals.