After a house a car is likely to be the second most expensive purchase you'll ever make. Stands to reason, then, that manufacturers are willing to spend top dollar to get you thinking about their products.

Quotes for advertising 'spots' vary but, according to figures from ITV, if you wanted a 30-second advert to run in London during its primetime Coronation Street at 7.30pm, you'd be looking at £14,872 per go.

It's no use telling customers in London about your new car if customers in the Midlands aren't getting a look in, though, and to broadcast the same spot to all regions means your costs will rise to £59,549. 

That's per advert, per time, too. Just think how many spots you'd be looking to acquire to secure a new product firmly in the nation's minds.

Take, for example, a big product like the new Nissan Qashqai. The firm wouldn't confirm exact figures – citing the fluidic nature of booking advertising spots – but said that any campaign to promote a flagship model would cost millions, instead of hundreds of thousands.

Adverts have to be able to do a lot in a short timeframe, too. According to Forbes, the ads that work best must have a story, clearly defined characters and catchy music. Viewers must be convinced they're watching a mini movie that just happens to feature a product. In short, the best adverts don't look like adverts at all.