I am exploiting the unfounded assumptions of others for personal monetary gain, yes. But I'm not lying, and there's a genuine difference.
Their assumptions are not unfounded. Panhandlers typically are in desperate straits and need the money. So you are not exploiting *unfounded* assumptions, you are exploiting a *common and well founded* assumption. Furthermore, typically people are polite and won't pry into details, when giving handouts to pan handlers, so you are exploiting the politeness of people that might otherwise want to know of your deception.
And there is no difference between lying and deceiving. Again, lying is not solely about factual correctness, it also contains elements of *intent*. If you intend to deceive, i.e. in this case exploit a common assumption by mimicking the behavior of those typically in need, bringing children to play to your victims' compassion, and relying on the cover of peoples' typical desire not to embarrass, you are lying.
When people give me money when I'm panhandling, they might very well be thinking - more or less incorrectly - that their dollar is going to buy much-needed food for a desperately impoverished man and his children, when in fact that dollar is going to buy me about 1/190th of another share of VOO for my portfolio. But they offered me the dollar because parting with their money on the basis of their stupid assumption made them feel good.
I would guess that they offered you money out of desire to help, not necessarily for some feeling of satisfaction.
This is no different than the manner in which luxury goods merchants ply their wares. Fancy companies sell t-shirts for $75, knowing full-well that there is no qualitative difference between their shirts and $5 t-shirts, and knowing that sucker consumers will happily plunk down the $75 because of the stupid and unfounded assumption that doing so will cause a benefit to inure to them (the love of sexy ladies, the admiration of strangers, etc.) Retailers know this assumption is bunk, and they trade on it for profit anyhow.
The analogy is flawed. In your case, you are mimicking the behavior of desperate people. People think you are desperate, and give you money. For the $75 T-shirt example, people know that there are $5 alternatives that are functionality equivalent, if not fashionably equivalent. For the T-shirt scenario, the buyer typically knows that advertising is selling a fiction. I don't watch an Axe body spray commercial and then reasonably think an army of hot women is going to emerge from an ocean, unable to resist my charms, if I use it. In your case, there is no expectation of deception, and the cover of the societal norm to not pry into finances (and to not embarrass), shielding you scheme.
What I'm doing is no different and certainly no worse. If anything, it's better, because I'm not exploiting some Central American factory force in the process.
It is different as I just argued. Regardless of that, I agree that advertising can be morally questionable, but that's a completely different debate.