Does advertising work?

Twitter has reported its first quarterly net profit helped by a rise in video advertising sales.  BBC news story

That was despite the number of people using the social network coming in below expectations.  Twitter’s previous failure to make a profit had confounded investors given its widespread use and popularity among celebrities and politicians.

One of the biggest mysteries in life to me is how the BBC can continually promote Twitter and Facebook every hour of the day for free.

Unless I am wrong Twitter and Facebook are both businesses and the BBC is a public broadcaster funded by the license fee.

It will cover up the label on a bottle of sauce but promote Twitter and Facebook several times an hour everyday of the week.  If it’s not a direct advert it is certainly a free promotion and driving an audience to Twitter and Facebook.  How does that work?  If that is true should we consider the following.

How effective is traditional media advertising?

You could not afford to buy the amount of space given to the number of social media mentions in main stream media.  How much would a brand pay

for a top line news reader,  journalist or presenter to promote their brand?  Yet every hour of the day this happens free for Twitter and Facebook on the BBC and in the commercial sector.

So my question is “How effective is mainstream advertising if this is the first time Twitter has returned a profit in twelve years”?