Sale and cash are well understood in accounting circles. "Forward booking" is, I understand, much fuzzier. What may count as a sale (eg, I receive a purchase order) may differ from the forward booking (someone scribbles on an MoU).

Depending on the organisation, sales staff can be paid at different times in that pipeline. And unsurprisingly there's dropoff at each stage.

I guess I should end by pointing out that I am not an accountant and this isn't accounting advice.