The most ubiquitous pub in London turns out to be the Prince of Wales, which therefore appears in the largest font. Conversely, there is only one Leighton Arms, so this appears in the smallest font.
The diagram covers the whole of Greater London. Its data are drawn from various online databases, including Beer in the Evening, Fancyapint and CAMRA.
We went for pubs as there are simply too many bars to fit on one design (perhaps this is a project for someone else!) and pubs have a habit of keeping the same name for longer! We'd encourage any Landlords who think their pubs have been ommitted to get in touch (We will be updating the design in the future and do want to make sure we are as accurate as possible).