You need to take into account different situations that can occur when using ROI to measure your campaigns, and that can lead you to wrong conclusions. Let's give some examples:
A company launches a marketing campaign to increase brand awareness. The campaign has a negative ROI, but it has had a positive impact on brand awareness. If your goal was the latter, you don't have to think that the campaign was bad because it had a negative ROI. Another explanation could be that the company didn't take timing into account. The france number data ROI of a marketing campaign to increase brand awareness can take time to be seen. In this case, the company may have cancelled the campaign too soon.
Your ROI far exceeds your expectations, even though sales have not been extraordinary. This may be because the company has not taken into account all the costs associated with the campaign.
A company launches an advertising campaign to increase sales of a product. The campaign has a positive ROI of 20%. However, the campaign has not had a significant impact on sales. Perhaps the explanation may be that ROI was used as the only metric to evaluate the success of the campaign. However, ROI is not the only metric that we should take into account.