It is often the most valuable signal for segmentation and prediction, because money spent is a strong indicator of value and intent. It differs from behavioral data: transactional data records the economic event that happened, such as the order and its value, while behavioral data records what someone did around it.

In practice

If you can only connect one source to a CDP first, transactions are usually it. They anchor value-based segments and lifetime-value models. Before modeling value, confirm whether figures are gross or net and how refunds, discounts, and tax are handled, or the math will be off.