some of the biggest names on wall street and in silicon valley—jpmorgan chase advent international khosla ventures among them—are pumping billions of dollars into momandpops selling everything from tea kettles to jock itch remedies on amazoncom inc investment banks venture firms and private equity shops are backing socalled amazon aggregators—often led by ecommerce veterans—that are betting they can take upandcoming sellers who often operate out of their garages and transform them into global brands the aggregators say they have the expertise to select strong products and avoid faddish ones that flame out before they have a chance to grow