I don't believe in the keiretsu model of VC investing that was briefly fashionable in the late 90s. I don't think you can or should force your portfolio companies to work together. It has to happen organically, if at all. But when it does, it makes my heart warm.
I saw this post on the Etsy blog (called The Storque) yesterday. Apparently a number of sellers in the Etsy community are starting to use Twitter to get the word out on new stuff they have up on Etsy for sale.
My sales have increased since I started twittering. I think as sellers we're all looking for ways to get our great items just a few more seconds of publicity, an Twitter certainly offers that opportunity.
That's most excellent!
You can also follow The Storque on Twitter. I did just that yesterday.