Sweet Deal! How Candy Crush Made Billions

Garish graphics, cartoon sound effects and hideously addictive gameplay.

There are plenty of popular mobile games, but none which have had the reach and commercial success of Candy Crush Saga.

It (Other OTC: ITGL - news) 's a free game but manages to make billions by letting its users cut corners with extra lives and other bonuses.

At its peak, in the second-half of 2013, it made $1.03bn (£670m) from its in-app purchases.

It has been downloaded by half a billion people - many of those became hooked.

The game was responsible for a 7,000% increase in annual profit for developer King Digital Entertainment (NYSE: KING - news) , but its runaway success has made King look like a one-trick pony.

Despite 200 other titles in its stable, none have come close to matching the success of its biggest hit.

Meanwhile, its new owner Activision Blizzard (NasdaqGS: ATVI - news) boasts a varied library of big-name games including Call Of Duty, World Of Warcraft, Hearthstone, Guitar Hero and Doom.

Spending on King's titles is down, falling 13% year-on-year in the second quarter.

But King's 500 million monthly active users across 200 countries are clearly what's attracted the attention of Activision.

They're paying cash for King, and say that other than YouTube and Facebook (NasdaqGS: FB - news) there isn't a worldwide network with the reach of King.

The price tag of $5.9bn (£3.8bn) means King is being sold for $18 (£11.70) a share, beneath the $22.50 (£14.60) it fetched during its initial public offering last year.

King was founded in Sweden in 2003 and it released Candy Crush Saga for mobile devices in 2012.

It has offices around the world - its corporate headquarters are in Ireland (Other OTC: IRLD - news) and its main offices are in London.

Mobile games now make up around $14.5bn (£9.4bn) of the $75bn (£48.6bn) in total revenue for the global games market.