Of course, tying up an expensive transceiver for long periods running WSPR is a bit of a luxury. That's why the diminutive WSPRlite units have become so meteorically successful.
So successful, in fact that if we take transmit powers of 23dB as a likely indicator of WSPRlite use on the WSPRNet reporting site, then between 40 and 50% of all stations on 40m last night at any randomly-selected period were transmit-only, WSPRlite units.
It's great to see so many people having an interest in WSPR, of course. But the whole system does depend on people listening. No listeners, no reports.
The worry is that WSPRlite has only been available for a couple of years, yet has reached a very high proportion of active stations already. In a few years' time, the skew might well work against the whole WSPR system.
Ideally, we need a cheap WSPR-dedicated, data-logging transceiver. There must be an opportunity for someone to produce something like this, with a mind to low power consumption and simplicity that permits it to be deployed in challenging and resource-limited environments.