what is a reason many advertisers end up undervaluing mobile’s contribution to conversions?

The reason many advertisers end up undervaluing mobile’s contribution to conversions is that they rely on a last-click attribution model to measure performance . This model ignores the clicks that may have occurred earlier in the conversion path from other devices. It is imperative to include calls and visits in the conversion column as mobile continues to impact more conversions than website conversions. Counting these could essentially lead to a reduction in the mobile CPAs.