At BMW's press conference last week the car company's chief executive Norbert Reithofer announced that his decision to leave F1 at the end of this year was "a resolute step in view of our company's strategic realignment." However, as with everything in F1, all you need to do is follow the money in order to get to the bottom of BMW's departure from the sport. The pot of gold at the end of its rainbow was rapidly running down.

F1's annual financial bible Formula Money, which is authored by Pitpass' business editor Chris Sylt, has launched a new service to open the window on team costs and sponsor returns wider than ever before. This service, the ROI Review, is published after every Grand Prix and gives financial data about the return on investment gained by teams and sponsors.

The ROI Review includes estimated media value of sponsors' exposure; print media exposure of team owners and title sponsors; the amount of money it cost each team to score a point; and the amount of money each driver cost the team per point he scored. This data will be available within hours of future races but since the first edition of this includes a summary for the season so far, as well as data from the Hungarian GP, it took longer to produce. It shows that BMW's financial performance has been just as wince-inducing as its ability on-track.

According to the ROI Review, each of the points scored by BMW in the nine races to Hungary cost the team on average $22.2m (£13.1m). By contrast, Brawn got best value for money with resources of just $0.6m (£0.35m) being spent on each of its points scored during the first nine races. Mirroring the on-track developments, Brawn was closely followed by Red Bull which spent $1.1m (£0.65m) per point scored.

Brawn's success made Rubens Barrichello the best value driver in F1 with each point he scored costing his employers just $10,000 (£6,000). However, the team's sponsors didn't appear to make the most of this since Toyota's title partner, Panasonic, is estimated to have got $53.2m (£31.4m) of media value - more than any other sponsor - over the first nine races.

The explanation for Panasonic having the best exposure is not just that Toyota had a great start to the season but also that the teams taking up most of the time on TV - Brawn and Red Bull - have no sponsors with as much coverage on the cars as Panasonic (Red Bull itself is not classed as a sponsor since it is a team owner). All the white space on the Brawn car was quite simply a waste of an opportunity for the team to make money.

This position changed in Hungary with McLaren's victory since the team's title sponsor, Vodafone, is well covered on the car. It had the highest media value of any sponsor in the Hungarian GP getting an estimated total of $9.6m (£5.6m). In total, McLaren's sponsors got $13m (£7.6m) in media value during the race - more than any other team. It was followed by Toyota whose sponsors got $9.9m (£5.8m) in media value - little surprise since it was the only team, other than McLaren, to have two cars finish in the points. In contrast, Brawn's dismal show led to its sponsors getting just $3.2m (£1.9m) in media value in Hungary.

Print media exposure is a different story - Mark Webber's victory and Sebastian Vettel's home popularity made Red Bull the team owner with the most print mentions in the week before and the week after the German Grand Prix. The print exposure for the weeks surrounding the Hungarian GP will be published in the next ROI Review since one week after the race had not yet passed when the first edition of it was published last week.

The impact of having big spenders dominating the race in Hungary is that Nico Rosberg's hard-earned fourth place made Williams the most financially efficient team there, with a cost-per-point of just $1.45m (£0.85m). Rosberg was also the best value driver of any team, costing Williams just $12,000 (£7,000) for each point. In contrast, Hamilton's hefty salary means that despite winning the race, he was only the fifth best value for money driver with each of his points scored in Hungary costing an estimated $118,000 (£70,000).