Lonely Planet has two main businesses: print publishing and web content/community. Assume that the company's publishing business does around $80m, which is a small boost on its 2001 sales. On the other side of the LP house, Lonely Planet's website gets 4.3-million unique users. Let's also assume the publishing side of company has 5% net margins (which is charitable). Finally, BBC says the deal was "comfortably" under its $175m cap for acquisitions, so let's guesstimate a value of $100-$150m for the buy.
With the preceding assumptions, the deal was done at about 1.1x-1.4x publishing sales, or 30x-ish publishing earnings. With a more typical publishing industry earnings multiple at closer to 12-15x earnings, then the balance is for the Lonely Planet's web properties, thus according a $60-ish million to Lonely Planet's 4.3-million web site uniques.
Granted, lots of assumptions here, but it's at least worth a ponder. Other thoughts?