I see what you mean. It may have all started when Marvel started to reprint books with completely different covers rather than the usual straight unaltered reprint of the original book. With the two examples in this thread, they even say 'variant' on the reprint cover so it's easy to see why that way of thinking sets in. My experience was that the second printings were produced in comparably low quantities and a few of the Spidey's went under the radar and gained popularity due to relative scarcity. For ASM, I used to get two of every second print from about issue 500 up. They did really well for me when I sold up, given that I purchased them at regular cover price, not the inflated prices of the 'proper' variants.