Many small or niche brands think that giant retailers like Walmart would never be interested in their brand. If the product is me-too, with a me-too story and a me-too consumer value proposition, they'd be correct.
But being small or niche, in and of itself is not a knockout factor.
A friend of mine was a Walmart buyer. He told me that Walmart buyers get the most recognition when they find a hidden gem and make it something. According to this former buyer, the view inside Walmart says that any idiot can make the latest launch by Coke or P&G or Unilever a success, given the brand's spending level. It takes a real merchant to spot an item with unique value and then drive within the Walmart system.
I have seen this phenomenon play out in numerous Walmart vendor meetings where the retailer touts the success of beer-coozie, beef jerky, $1.00 DVDs and scads of other "little trains that could".
Sometimes the sheer expense of building inventory and the risk of absorbing a potential huge return is too daunting a task for a small brand, and rightfully so. Just don't count yourself out just because you're small or niche.
O.D.O.o.O.D.B.