Lee Gomes at WSJ and Chris Anderson have gotten into an interesting debate about the validity of Chris’ thesis that the “long tail” represents a significant economic paradigm shift. Unless I’m missing something, there is one element missing from the debate that anyone conversant with Umair Haque should recognize.

The debate between Lee and Chris focuses on whether sales in the long tail for any category can and will make up a significant percentage of total sales.

The long tail theory is often misconstrued to mean the end of the hit/blockbuster. But in fact the hit/blockbuster is still a significant aspect of long tail economics.

What changes — and this is the missing piece — is that in a long tail market hits can more easily emerge from the long tail through the power of network effects, or what Umair calls the “Snowball Effect.”

When you combine deep online catalogues with sharing/online social tools/viral marketing/etc., it becomes easier for any given item to become a sales “hit.”

Just look at Chris’ book, The Long Tail. It’s currently #16 at Amazon (up from #17 earlier today before the debate hit Techmeme). It may well have been a best seller without the network effect, but Chris’ long tail blog and the conversation he has fostered during the period when he was writing the book and all of the conversation that has ensued post publication virtually ensured it would be a sales hit.

Fifteen years ago, it would have taken a large marketing budget to achieve the same effect.

Now Chris was able to create a best seller for the cost of a Typepad account.

So for me, the radical long tail notion is that it’s no longer necessary to “buy” a hit — you can leverage the socialization of the web — combined with the web’s unlimited shelf space — to generate a hit from the bottom up, virtually for free.

If the Internet levels the playing field for hit making, and dramatically increases the economic efficiency of hit making, that would indeed be a HUGE sea change.