I am not well informed regarding Sezzle so won't comment there....

I am not well informed regarding Sezzle so won't comment there.

I've had a good look at Affirm and note the following:
1. They are a large competitor (~5-10x Zip US revenue) that operate in a very similar space to Zip's instalment products (now pay-in-8 also), however, they have historically tended towards longer duration loan products (multiple months+) enabling a higher revenue to TTV margin of ~10% (but slower turnover of capital).
2. They are not yet profitable but are approaching breakeven as a result of significant reductions in their operating expenses relative to revenue over the past four years (EBIT margin was approximately -50% of revenue, and is now more like -5-10% of revenue).
3. They are advantaged relative to Zip because a significant proportion of their operating cost base (~20% or ~$500m USD per year) has been paid out as equity to employees rather than cash. This has enabled them to grow without weakening their balance sheet too much over time (despite making heavy losses).
4. The interest expense incurred on their debt is much lower than Zip's (~2-3% lower rate - but potentially more than this relative to Zip's US debt which appears to have a higher interest rate than their Aus debt).
5. I have not done any detailed valuation work on Affirm, however, it also appears generously valued relative to its net tangible asset position (priced at ~10x NTA) and prospects of future profitability in what is a highly competitive market (PayPal, Afterpay, Klarna, Zip, Sezzle - the list goes on and on).

Regarding Zip's active users becoming financially stretched, I outlined why this is the case using data taken directly from Zip's 2025 H1 financial report in an earlier post:
https://hotcopper.com.au/threads/2025-h1-true-ebtda-cash-ebtda.8465359/page-8?post_id=78053125
(this post also answers your question about the "true bad debts" situation)

Regarding new customer acquisition:
- I didn't say Zip were unable to do so, I was actually highlighting that it is materially the same group/cohort of users who have provided the significant revenue growth. This is what has caused them to become financially stretched as on average, each active user is now being lent ~40% more than a year ago. For obvious reasons, at some point this approach stops working.