To add to your "line extensions TK" file, consider the example of Rolling Stone magazine, which is launching a wine club, inspired by rock music.
The magazine has partnered with Wines That Rock, which creates wines with labels inspired by rock-and-roll album covers.
A one-year $12.95 subscription to Rolling Stone is included with the initial wine club membership, which costs $39.95 per shipment of three bottles of wine, four times a year plus $14.95 shipping and handling and tax (our math says that means a membership costs more than $240 a year and each bottle costs roughly $20.)
Each shipment offers a different set of wine, with current featured wines including the Grateful Dead Red Wine Blend, The Rolling Stones Merlot, Pink Floyd’s The Dark Side of the Moon Cabernet Sauvignon, The Police Synchronicity Red Blend and Woodstock Chardonnay.(The wine club only delivers to addresses within the U.S and even then not to all 50 states, some of which have quantity or other restrictions.)