(1) Hugely improbable specialist etailers like iwantadoor.com advertising (indeed sponsoring) prime-time TV shows. When I saw them appear in the sponsorship slot tonight I immediately knew I was looking at the next Pets.com. That's not a happy connection for any company and it's not a happy moment for our market.
(2) Massive valuations placed on stocks that have never returned a profit. Demand Media (even with all its weird accounting) still wasn't making a profit when it got listed at $2bn. HuffPo just got bought as it went into marginal profitability. People are spending billions to own businesses that have yet to return a penny. That's not healthy, rational investing. That's dumb money hitching itself to a rising bandwagon (yes, I just said "rising bandwagon") and hoping to offload the shares before it falls.
(4) Legacy media companies scraping around for a last throw of the dice (and make no mistake, AOL has been a legacy media company for a while) paying absurd per-user valuations for much younger pureplays and making optimistic noises about synergies that will clearly never come to anything.
(5) A Superbowl ad roster full of pretty feeble ads from dotcoms. Groupon's ad seems to have harmed the brand in fundamental ways. GoDaddy's seems to have given the Twitterverse an excuse to point out how much they hate GoDaddy.
(6) The increasingly astronomical valuation for Facebook. Sure, I've written myself that if you believe that everything will come together for Facebook and nothing will go wrong $50bn is just about credible. But it doesn't take much for the world's leading social media property to become so much worthless paper.