Irregardless of whether my assumptions were correct or not... the OP should not disadvantage himself by being on the other side of the table to someone like me or someone worse than me...
To be perfectly honest if you run a casual office yet judge people on their appearance at interviews, I'd call that rather hypocritical. Perhaps you should think why it's acceptable for your staff to dress down, but not your interviewers? Afterall, if your staff are meeting their customers in jeans and tshirts should that not be good enough for
you?
Indeed, the only real exception is Google who make it known they prefer weirdness in their employees and request casual attire.
There's a very simple way to look at it: Will a suit hurt your chances in an interview? Almost certainly no, will not wearing a suit hurt your chances in an interview? Almost always yes.
It's good it "appears" the OPs decision didn't hurt him too much but it's still better to play it safe.
Google aren't some almighty exception to everything. There's a million companies out there that probably run their offices in a similar way. I know, I share a building with Google...
I already posted reasons why a suit could work against you;
- Shows lack of experience working in that type of company/role/environment
- Shows a lack of understanding of the workplace and people you'll be working with/for
- Shows a lack of creativity (kinda important for a creative role)
You say it "appears" the OP dressing casual didn't harm him, why won't you admit it may have been advantageous?