San Francisco's Chronicle is the latest newspaper to report on the new thriftiness among Silicon Valley's entrepreneurs. Riya's boss boasts, as he did in last week's Wall Street Journal, that the photo search company has enough cash socked away from its two funding rounds to last till 2009. Rapleaf's Auren Hoffman, always one to give a quote or fix his own Wikipedia page, says he's so cheap that the reputation brokering startup doesn't even have a sign on the door. So why the spate of interest in burn rates, and why, even more perplexingly, the willingness of startup bosses to attach their names to such an awkward topic?

The media interest isn't that surprising. Three months have passed since the last giant exit, the sale of Youtube to Google for $1.65bn. The makers of most new web applications have no meaningful revenues. And there'e one obvious question, the same one that Barron's asked to such powerful effect in March 2000 in Burning Up, a cover story that pricked the last internet bubble: how long will, barring additional investment, the money last?

There's some value in a firm establishing its staying power. Since the holidays,at least a dozen ventures have disclosed the departure of founders, layoffs or closure. In crowded fields such as online video, there's a widespread assumption that 90% or more of the ventures will run out of funding. Heavily funded companies, such as Slide among the photo slideshow apps, do have more credibility as partners and more negotiating leverage as acquisition targets.

However, I suspect that many entrepreneurs are simply promiscuous in their interview policy. Uber-networker Auren Hoffman, for instance, volunteers his opinion on everything from the sporting prowess of women he dates, through to the rent he pays. Any publicity is good publicity, goes the theory. Wrong: this topic is toxic. First of all, any startup that appears in an article on burn rates is advertising its lack of revenue. Second, to boast, as does Riya, that the company's warchest remains largely intact: that's just a public invitation to investors to push for liquidation before those assets drain away.