True, the the profit does directly flow from the amortisation...

True, the the profit does directly flow from the amortisation rates used. I suspect that CCP are a bit more sophisticated than you infer. My assumption is that each ledger is considered individually and that there is no overall company wide rate, which explains why they don't publish a single rate.

Perhaps a more concrete way of interpreting the profitability a credit collections company is to look movements in borrowings. In the 2011 the net repayment of borrowings was $18m (after paying a dividend of $7m). I interpret this as their cash flow profit. Note that 30 June 2007 CCP had $125m in long term borrowings but on 30 June 2011 their long term borrowings were zero, a massive turn around. At this rate the company will either have no borrowings at all by Dec 2012 or it will have used it now very strong balance sheet to expand into new business.

All financial services companies amortise anticipated forward cash flows money they will receive/payout in the future. Life insurance companies for example make similar assumptions about how many claims they will pay out on in future years. These assumptions go directly to the bottom line, well before any claims are received. Any inference that something arbitrary and unfair is happening at CCP is most likely the result of distance from and general ignorance about the credit collections business.