An internal campaign banner is one that points to the same site it is contained in, for example you may advertise for one of your products while the user is looking at another one.
For banners hosted in external sites the best way to collect statistics is to use UTM
(Urchen Tracking Module)
query parameters: Google Analytics
can automatically collect and group this type of data.
On the other side, the UTM approach is not good for internal campaigns, because when mixed with external ones, it compromises the analysis: try to imagine what happens if a user clicks on an external banner, then in an internal one and finally she makes a conversion. Which is the cause and which is the effect?
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