For many online retailers, the share of pay per click (PPC) revenues from mobile devices is rising across the board.

While the overall percentage of PPC that mobile accounts for remains small, it is growing quickly with some retailers seeing 600-900% year on year increases in mobile's share of PPC revenue from advertising through Google AdWords. By default, PPC advertising campaigns are already syndicated through mobile devices. You can examine the impact that mobile is having on the profitability of your campaigns by running reports in the "Campaigns" tab within AdWords. If your return on investment is low on ads that are served via mobile devices, consider disabling syndication to mobile temporarily. If your ROI is high, though, you can try to scale those profits even further. One way to do this is to build campaigns devoted specifically to mobile.