Return on investment is an important measure. In marketing, though, it is notoriously difficult. Among the reasons is that most larger brands use multiple channels and touch points, but tend to measure and attribute returns based on a single channel.
Many, for example, attribute sales to the "last-click" by a buyer, while some might atribute an ultimate sale to the "first click." Others, with channel partners at work, will recognize a sale as coming from that channel, essentially ignoring all the work done by all the other channels, or the touch points that might have contributed to a sale.
First-click and last-click attribution models are easiest to measure, but their use can over- or under-credit an ad format’s influence on conversion activity.
For instance, February 2012 data from Adobe measuring revenue per visitor to US websites, broken down by attribution model, showed that search generated 38 percent more revenue when measured via first-click attribution than last-click.
Social’s first-click slant was even more dramatic: 88 percent.
Additional Q1 2012 findings from digital marketing firm RKG showed similar differences.
The point is that a "one-touchpoint experience" is atypical for internet users and not a good measure of digital effectiveness. Nor is that common for complex products sold to business customers, either.