Spiders do suck actually... those big nibbly bits are just for mashing stuff into soup.
Most spiders have digestive enzymes as part of their venom - hello brown recluse! - which makes the flesh either drop off or go all mushy. The pink toe, afaik, instead vomits digestive enzymes directly into the mouth of its prey, and lets it dissolve from the inside out. Strangely for spiders, they can live in colonies without attack each other cannibalistically. Lovely little things.