Microsoft has bolstered its Internet commerce capabilities by purchasing Jellyfish, an innovative comparative shopping site, for an undisclosed sum. Jellyfish will remain a standalone entity, but Microsoft's Web team has signaled they will be borrowing Jellyfish's technology for use across the software giant's websites. Why? Jellyfish introduces a compelling new twist to comparison shopping. Listed retailers only pay Jellyfish when purchases are made — the more they pay, the higher they rank. In turn, Jellyfish kicks back half of its commission to the buyer, effectively lowering the price. It's an intriguing business model, taking a page from Google's ad-ranking technology and applying it to e-commerce. Just one problem: Microsoft's unfortunate track record of crushing the life out of small, innovative companies it acquires.