To some degree the answer depends on what you need from a physical location. Some of the benefits you get with London: * Density of people with expertise - eas

To some degree the answer depends on what you need from a physical location. Some of the benefits you get with London: * Density of people with expertise - easy to hire or find people with specialist skills * Variety of talent levels - getting people at the right level if you're building an extended team * Availability of people with similar experiences - support groups; shared space * Availability of support services - legal, financial, VC * Supportive employment and tax region - UK rather than London specific * Large market for testing and product validation - UK is both a gateway to Europe and has similarities to the US if you're moving your product from Europe * Language and time zone advantageous if you are multi-region If you're a light-weight start-up with a small team that has all the skills to create and bring the product to market then it may be less important. If you're likely to grow into a small company (say you're VC backed) and need lots of different skills then London has advantages - these are the same advantages any large city or Silicon Valley has and they vary to degrees. Note that in that scenario direct cost of salary is only one element in the total cost of running the business.