If you've tried all of those things and haven't gotten any customers, the problem isn't your advertising method, it's the message.

Think about who your customer would be. Who uses an online bakery? What motivates them to buy baked goods online rather than going to the bakery down the street and getting to experience the wonderful smells and atmoshpere?

Is it lazy people who are too fat to leave the house? That would make for some funny advertising possibilities but I'm guessing it's going to be people looking to send baked goods as a gift.

So if you are going after people looking to send baked goods as a gift, make your advertising speak to those people. Don't send out "Hey everyone, come to our website and buy some stuff..." send out "Feel guilty about not calling your mom enough? Make up for it with muffins! Free shipping if you order before (date)." or make it about upcoming holidays or whatever...

Hope this helps