On Tuesday afternoon, representatives of the tech industry’s biggest corporations convened at Facebook’s Palo Alto, California, headquarters.

The attendees were not engineers or Internet monetization experts, but a less celebrated breed in the Silicon Valley landscape: public relations officials.

INTERNET-SOCIALMEDIA/PRIVACYFacebook had summoned the hard-working spinmeisters to Palo Alto make its own pitch to them.

Dozens of “flacks” (as those in the PR trade are affectionately referred to by reporters) were escorted into Facebook’s cafeteria for a series of briefings by a team of Facebook officials that included Randi Zuckerberg (the sister of 26-year-old co-founder and CEO Mark).

With half-a-billion users, Facebook has become an established platform for everything from video games to e-commerce. The purpose of Tuesday’s unusual gathering was to showcase Facebook’s strengths as a public relations tool for companies.