Dell had a reputation as a company that relied upon supply chain efficiencies to sell established technologies at low prices, instead of being an innovator. By the mid-2000s many analysts were looking to innovating companies as the next source of growth in the technology sector. Dell's low spending on R&D relative to its revenue (compared to IBM, Hewlett Packard, and Apple Inc.)—which worked well in the commoditized PC market—prevented it from making inroads into more lucrative segments, such as MP3 players and later mobile devices. Increasing spending on R&D would have cut into the operating margins that the company emphasized. Dell had done well with a horizontal organization that focused on PCs when the computing industry moved to horizontal mix-and-match layers in the 1980s, but by the mid-2000 the industry shifted to vertically integrated stacks to deliver complete IT solutions and Dell lagged far behind competitors like Hewlett Packard and Oracle.