The quora experts exchange parallel is not a fair one. Expertsexchange attempted to get you to pay for membership to view the answer (it was available impossibly far down the page so google would index, but obscured as much as possible). Quora prompts you to create a free account after a couple question views, which is infuriating as a user(imho probably not going to be worth it from a business perspective either), but thats a pretty big distance from deceiving you into paying.*

*admittedly Quora's total lack of a revenue model at the moment helps them out here.