You pay only out of the revenue the campaign actually recovers.
I run the whole thing: the segmenting, the writing, the sending and the tracking. Over the sixty days after it goes out, the fee is a share of the revenue it brings back, settled against the click and booking tracking rather than against a feeling.
There is no setup fee to fall back on, so the rate carries the risk. If nothing comes back, the campaign cost you nothing.
$0 UP FRONT · 20% OF RECOVERED REVENUE