It's no free lunch, but Microsoft is sponsoring free Boingo Wi-Fi access in San Francisco and New York City to generate buzz around its Windows 8 launch. And, honestly, most self-respecting techies would forgo food for free on-the-go Wi-Fi anyway.

The service went live on Monday in six Manhattan subway stations and several San Francisco destinations, including Union Square, Fisherman's Wharf and Nob Hill. Starting November, Microsoft will expand the service to 200 Manhattan locations.

But don't expect free Wi-Fi without some strings attached. When users access the Microsoft and Boingo Wi-Fi, they'll be directed to the new Windows Store (the Windows 8 take on Apple's App Store or Google Play). Microsoft says it is making free Wi-Fi available in San Francisco and New York City specifically because "amazing apps are being built in New York and San Francisco, and we want to give talented developers the chance to launch their businesses through the Windows Store."

The Wi-Fi hotspots are part of Boingo's Cloud Nine platform, which allows companies to advertise its products through Wi-Fi sponsorship.

Microsoft hasn't announced an end date for the promotion, so get out there and start using the subway station as your new office while you can.