You were actually employing a tiered "single sign-on" strategy without any of the convenience of SSO. For the vast majority of sites, the site being compromised is inconsequential. e.g., So What if my local newspaper site login was breached?
It makes an awful lot of sense to have, say, 3 OpenIDs. One where you just could care less; used in the majority of sites (say, 70%). One where you'd rather not lose them (say 20% like your Amazon, eBay, iTunes), and one used for the last 10% that you guard zealously like your bank, email or whatever.
Beaten to market by a few months!
I think being a bit delayed can be quite positive for your project. Sure, no first mover advantage. But at least now you can see ahead of time what works and what might not and adjust accordingly.
It's called Poe's Law. Look it up.
For those who don't want to look it up, here's from wikipedia:
Poe's law (poetry) — There is a maximum desirable length for poems: "The unit of poetry must be fixed by the reader's capacity of attention, and
Pause for storage relocation.