A cold call could come through at exactly the right time and 'get lucky', but it's not very likely. Over time, and with enough hounding, they might eventually remember your name and call you when they do have a requirement. But again, it's pretty unlikely. Cold calls are pretty much a waste of time for both the caller and the recipient. Very invasive too, and they always call from a 'withheld number' so you can't easily filter them out. I guess it's the 1 in 1,000 mentality that keeps people doing these things. Kind of like spam - it's just a numbers game before you get a bite on the hook.