Coca cola, pepsi, lays etc why do companies need so much of advertising all over TV's, internet, sports events...even after becoming a household brand.
how much percentage of their profit usually they keep for advertising?
if they cut down on so many advertisements, then many products can become cheaper or pass the profits as dividends to shareholders.
It's pretty simple: those brands that are advertised so much are typically commodities, meaning they are pretty easily replaced by another brand's similar product. So they want to stay top-of-mind, so that when you reach for a soda, you remember Coca-Cola.
Beyond that, YOU may know Coca-Cola from seeing thousands of ads for it over your lifetime, but the impressionable 14 year old next door might not. So they want to keep pounding that message ("Coke = Happy") into his head, too.
In the end, the more replaceable and less important an item is to consumers, the more the company is going to push it to a mass audience. Switching from Coke to Pepsi, PC to Mac, or even Chevy to Toyota, is ultimately not that tough a decision; but you don't see Twitter advertising much, because they are fairly unique in the market and they're already top-of-mind when you think of "social network / microblogging platform."
Remember: Your $1 may not mean much to Coke, and even your $5,000 lifetime revenue might not mean much, but if 10,000 people like you suddenly switch to Pepsi, that's a lot of carbonated sugar water that they aren't selling. So they're going to keep pounding away with ads as long as people keep buying their products.
Regarding the percentage of revenue that goes into advertising: For the famous Austrian energy drink Red Bull, in 2008, they invested 1.5 billion EUR into marketing; their 2007 revenue was 3.1 billion EUR.
Why do you think they're household brands? Everyone knows about Coca-Cola and McDonalds because they're everywhere. Household brands have to spend a lot of money or they'll "fade out". I've heard that McDonalds -- or, more specifically, their reduction in advertising in the 1990's recession -- helped TacoBell build its brand tremendously.
The most simple answer: It works for them. Never change a running system. ;)
Seriously, it's just one sort of competition. Some companies engage in price competition (usually retailers, think Wal-Mart or Aldi), some in product competition (often B2B or technical products), and some in brand competition, usually the premium segment. Sometimes, it's a mix with no clear emphasis on one possibility.
Thus, they can't simple cut some advertisements here and there. Loss of mind share results in loss of market share, and you happen to end with about the same profits as before.
Concerning your question about profit/advertising percentage: That's seldom used, since profit depends on so many other factors. I do recall a study of the effects of the advertising ban in the cigarettes industry, though. Unfortunately, I don't have it handy or can recall the authors. But if I remember correctly, profits increased by about 6% after the ban ; indicating that these companies were caught in an advertising arms race.
More common, however, are studies about the revenue advertising percentage: According to studies by Go-To-Market Strategies (GTMS), most companies spend 3-10% of revenue for promotion.
It seems a save guess that household brands spend even more.
Hope this helps.
The ads are also a way for these large companies to rebrand to appeal to a different market. So, you will see different types of commercials that are targeted to different markets, so the young adults/teens will see the energy drinks, which will be different than how they advertise to older families, or people that will be more influenced by the cute polar bears.
Also, as JoshSamBob stated, they have to appeal to the newer people that are no so set in their brand loyalty yet.
I have watched Mountain Dew, for example, change their mottos, just as the Army has done, as they try to find new ways to appeal to people, it is a constant balancing act. If you stay with the same motto, the same message, you will be tuned out eventually, and just die away.
So, these companies have to keep being fresh, so that they can be in the mind of their market.
Other than the reasons already posted:
A former salesman for Schlitz (They use to be a household name in beer.) who was chastised by "old man Schlitz" for not spending all of the money in his budget. They ran the numbers on what they made when sales people spent their marketing dollars on local bars and restaurants. I think Coke knows as well.
Schlitz thought they could make more money by creating a cheaper beer. That and the beer industry went to the distributor model which makes it tough to get into the industry (Don't be confused by some so called micro brews; they're owned by Bud.)
They've recently found their old recipe which is so much better than Bud or Miller. Better late than never, but can you imagine the marketing dollars they'll have to spend to get back to the top? Obviously taste doesn't count.