I promise I'll stop beating this horse, but I just read this post from NoBullGrape (who discovered our list of winery blogs) and it clearly states why a winery might want to blog in order to (ultimately) sell more wine:
...the more I know about a winery, its commitment to its particular land and the people behind the label, the more likely I am to buy their wine. Kudos to those already doing this and looking forward to discovering many more winery blogs in the coming months.
Update: here are some additional words on winery blogs from Dr. Vino:
Winery blogs, however, are not only sales and marketing pitches but also have the advantage of giving those of us not present a window to the harvest. I'm just waiting for the first "winery cam" in the vineyard...
A personal face is the thing that distinguishes smaller wineries from "corporate wineries" and a blog can help establish that personal face among your readers.
(PS - there's already at least one vineyard webcam at Bonair Winery in Zillah, WA)