So much marketing evaluation is tick-box in its approach: there is a feeling that it is the proper thing to do, but often this leads to a token effort, a fig leaf of respect for the process of continuous improvement.
Certainly it is extremely rare for organisations to devote the recommended 5-10% of their overall marketing budget to evaluation. But it is not always necessary to spend at this level to gather actionable evidence of what works and what does not.
Complex econometric solutions can be appealing and are often persuasive, but evaluation approaches can be much more simple and relatively inexpensive, provided the evaluation design is completed (or at least thought about) right at the outset of the marketing planning process.