Goods and services. In terms of their core business, the money they charge British companies to advertise on the Google network should be taxed and paid to the UK government. I don't understand the problem?
If their US company is wearing all the expenses then they get a tax saving there.
They are trying to have their cake and eat it, and declare expenses in high tax regions and profit in low tax regions. Hence Ireland being popular.
It's not complicated unless you actively start trying to move money around to avoid tax, which is what they all do.