Nintendo Wii vs PlayStation 3
Most canvases start from one choice, usually the customer segment, and the other eight blocks have to live with it. To compare two businesses, find the choice each one made first and check whether the rest of its page agrees with it.
In 2006 Nintendo and Sony launched consoles for the same shelf. Nintendo aimed the Wii at casual players, people who did not think of themselves as gamers, and promised motion control and fun. That promise did not need cutting-edge hardware, so the Wii could be built cheaply and sold at a profit from launch.
Sony aimed the PlayStation 3 at committed gamers and promised maximum power. Power meant a custom Cell processor and a Blu-ray drive, and those parts cost more than the console sold for.
Every Sony block followed from its first choice, and the chain ended on a bottom edge that lost money on each unit. Sony was betting that parts would get cheaper before the losses ran too long. The Wii went on to sell 101.6 million units, ahead of the PS3 by most industry estimates.
Run the same comparison on your own competitor. Name the block each of you chose first, follow it down the page, and read both bottom edges on one unit.
Two accounting firms serve the same town. One chose 'fast-growing tech start-ups' as its segment; the other chose 'local trades businesses'. Where should you look first to predict which page holds together?
Follow each firm's segment down its page and compare the bottom edges on one client
Compare the two firms' offices and headcount
Pick the firm with the larger potential market
Compare the two value propositions on their own
The segment each firm chose first decides what it has to promise, what skills it must hire and what it can charge. Following each chain down to the bottom edge shows whether the price that segment pays covers what serving it costs. Office size or headcount only matter as part of that chain.