This is common with Asian manufacturers.
If the cost to ship the product overseas (and have them return a "new" or "fixed" item) is too great, then an up-front replacement is often offered.
The issue is defining with the manufacturer what should be a fair amount of product as substitute for warranty.
The manufacturer will ALWAYS understate their actual returns (we have done this with 3 manufacturers and in all 3 cases have had to re-adjust the quantities upwards after the first year). In one case, the manufacturer had stated a 2% "extra" policy (saying this was their actual annual failure rate) but it was upped to 6% in the second year (when we had the actual numbers).
Another thing to be careful of: you need to exclude any "recalls" or "extremely unusual returns" from the deal. If they produce a batch of 1000 widgets and they all go bad, this cannot be your cost to assume.