In order to use Google Analytics and Adwords sensibly, you need the Conversion ID. This is stored in the Shopware Google Plugin.
The Conversion ID can be obtained via Adwords. There via Settings (click on the wrench) > Measurements > Conversions
The conversion ID in this example is: AW-961433594
The Conversion ID is then entered here. In case of several subshops, the conversion ID can of course differ and be generated for each individual shop.