Doubtful... my guess (since I don't care enough to actually read their financial statements) is that the lower CPC is because mobile is growing faster than desk

Doubtful... my guess (since I don't care enough to actually read their financial statements) is that the lower CPC is because mobile is growing faster than desktops.. and so they're getting more mobile clicks (which pay less). So in this case, after it's averaged out, they end up with a lower CPC.