What the Hell are Marketing Purposes?

I’m being targeted by marketing gurus. They’ve somehow got my number and I’m on some kind of list to get my details for something. I keep adding their number to a blocked contact that I’ve named Timewasters. I’ve now got 96 listings and the list slowly grows if they decide to call me from a different number. The friendlier one usually asks how I am and asks if it’s OK to ask a couple of questions. They want to confirm my address and I ask why and they tell me it’s for marketing purposes. So you now want to send me even more marketing content? When they called me in May I got charged for the call because I was overseas even though no-one spoke at their end. So I’m looking forward to the next one as I’m now going to bill them as soon as I’ve got their number.