SZL and Z1P make for a good comparison.
SZL went from 100k customers to 500k customers in ~ 3 quarters. It took Z1P 4 quarters to achieve this. 1.5 years on Z1P is a $1.2B company. I'd say SZL could get there in half the time at this rate, simplistically would value SZL $6-7?
Z1P January 2018:
SZL is also a much more capital light business, it funded $US43M worth of transactions in the most recent quarter and exited with receivables of only $US11M. This shows it doesn't need to raise too much capital to fund large amounts of volume, just like APT. SZL could fund $1B annual transactions with just $60M in receivables, could be a 50-50 debt capital split, so already has the capital requirements after its $US30M raise.