This detailed article from Horace Dediu at Asymco discusses how important mobile is to Samsung, and just how much they are spending on advertising and sales-related expenses (commissions, incentives).
It might be surprising to note that Samsung spends considerably more than Apple and Microsoft. But it also spends more than Coca Cola, a company whose primary cost of sales is advertising.
However, advertising is not the only form of promotional spending. Samsung also pays commissions and “sales promotion“.
They are in this to win, which is one reason they are the only company besides Apple who are showing profits in mobile. You can bet that this will eventually translate into more influence over the Android platform, if not an outright purchase.