There's mileage running, and there's extreme mileage running. If you didn't know already, one of the most efficient ways to hit British Airways Gold is through flying American Airlines domestic first class. However, there are occasionally other routes which provide decent value if you can't get to the other side of the Atlantic.
But Will is going for the top status available to normal civilians. With a threshold of 5000 tier points, he will attain Gold Guest List if all things go well, and earn around 200 000 Avios and 13 000 On Business points in the process. All within 40 flights!
I took a look at his blog, which also details his routing. He will fly the following itinerary all in business or first class:
1. London Heathrow to Brussels
2. Brussels to Helsinki
3. Helsinki to London Heathrow
4. London City to New York (on British Airways' special all-business class route)
5. New York to Los Angeles
6. Los Angeles to Honolulu
7. Honolulu to Los Angeles
8. Los Angeles to Orlando
9. Orlando to Miami
10. Miami to St Thomas US Virgin Islands
11. St Thomas US Virgin Islands to Miami
12. Miami to Los Angeles
13. Los Angeles to Honolulu
14. Honolulu to Los Angeles
15. Los Angeles to New York
16. New York to London City
17. London Heathrow to Helsinki
18. Helsinki to Brussels
19. Brussels to London Heathrow.
Assuming the Miami to St Thomas sectors above are in Business Class, by my calculations the above itinerary should yield 2480 Tier Points (= 210*10 + 40*8 + 60), which means he'll need to do another run like the above, plus a couple of flights here and there (if he hasn't got the tier points already) to hit the magical 5000 tier points.
Like most of the commenters from the Head for Points post which prompted me to write this, I reckon he's made good use of 3 tickets nested within each other: London to Brussels return, Brussels to Honolulu return, and Honolulu to St Thomas return. It also shows excellent usage of Maximum Permissible Mileage ticketing rules.
So what's the point? Well I could try to convince you using all the maths, but it's all moot when it comes to something as physically demanding as his journey. Let's just leave it as…this hobby is addictive (!).
Will, I salute your courage and lunacy!