Sorry to hear it didn't work out.

If one thing, this thread has given me some hope. Not because of your failure but because of how much positive response there was to it. How many serious threads have you seen lately where the replies outweighs the trolling? Even more, understand and empathetic replies with valid feedback.

And with regards to your site, there's so many things to take into consideration. The hoarding might not help things but cards are a small market, bitcoin is a small market, repeat buyers who will keep you afloat by themselves is probably even smaller. The more precise you get within an already relatively small market, the smaller your share of it will be. I don't see how it would have even been possible for that store to be a success based on how specific it it is, unless you had access to some really rare stuff, had competitive prices within that limited market, were able to advertise to a broad enough audience and stay open long enough for the word to get around...

Every failure is a lesson which will get you closer to success. You don't just "succeed". You learn to succeed. Every failure is just a sign that you're getting closer, as long as you're willing to learn from it and accept some criticism.

I hope for you that you're able to take a step back, look at the big picture and extract what you needed to learn from this. Leave the bitterness behind and translate that to enthusiasm thinking that next time around, you'll do X and Y differently and can't wait to see what the results will be, hopefully better than the first and lead to an even more successful third attempt.

I'm currently working on a site to help promote bitcoin and merchants that accept coins. Hopefully it wont be a total failure but regardless of how much it cost me and how much dev time I spend on it, I'm learning while doing it and knowledge is priceless.