You are flipping, faster and faster, through Time magazine, racing to get past the grim stuff (stories about the Iran-Iraq war and Raisa Gorbachev's manners) to the safe haven of the back of the book. Suddenly as you turn a page, a bottle of brandy jumps up and bites you on the nose.

It is only a folded paper pop-up replica of a bottle, and it does not really bite, although that is not from lack of trying. Trying too hard is the spirit of contemporary advertising.

Many a reader has been startled out of a year's growth by these advertisements that lurch up from ambush in magazines. They are like the pop-up bunnies of children's books. Pop-ups for grown-ups: perestroika on Madison Avenue.

Ordinary advertising is losing its power to get attention and shape appetites. This matters. America is a nation inured to the temptation of thrift, but advertising is nevertheless important in keeping the money moving in consumer spending, which accounts for $3 trillion of our $4.5 trillion economy.

Part of the problem is advertising clutter. The typical American is exposed to approximately 3,000 commercial messages -- from newspapers to billboards -- a day. It is said the average American spends a year and a half of his life watching television commercials. The number of messages transmitted by broadcast and print media doubled between 1967 and 1982 and may double again by 1997.

The sense of clutter is especially intense on television. Because 30 seconds of prime time can cost an advertiser hundreds of thousands of dollars (in the 1950s you could run an epic-length 60-second commercial -- the standard length then -- for $15,000), there is a shift to 15-second formats.

Add to the regular commercials the five-second network promotions and it is not surprising that viewers feel abused. They can be bombarded by upwards of 50 messages in a prime-time hour. But they can fight back.

Half of America's households have VCRs. Viewers can rent entertainment without commercials, or they can tape network entertainment and hit the fast-forward button when the commercials appear. Television sets have remote controls that enable viewers to mute the two-minute commercial ''pods.''

And now here comes the staccato future: on Japanese and European programs, there are 7.5-second commercials. That is long enough for ''reminder'' advertisements of products as familiar as, say, Coca-Cola.

To make the most of whatever hold they get on our attention, some advertisers are melding commercials: Coca-Cola, which owns Columbia Pictures, has advertised a movie within a soft-drink commercial. Miller Lite has advertised itself as just the stuff to wash down Frito-Lay products.

Some television commercials are avoiding hummable jingles that hymn the glories of, say, an antacid. Instead, they are using odd noise -- droning, panting, buzzing and other sounds -- that psychologists say can trigger emotions and stimulate cognition. And there are zany ads: the bar of soap that foams in a man's pocket, the Isuzu ads that label the pitchman a liar.

Most amazingly, some advertisers have fallen back on language -- plain words -- to communicate. These less-is-more ads put words on the screen, no pictures.

What will they think of next? New places to put advertising, that's what.

''Alternative media'' are getting a growing slice of the nearly $100 billion spent annually by American advertisers. Advertisements are appearing on parking meters, ski-lift towers, bus shelters, supermarket shopping carts, on closed-circuit television in supermarkets, on giant television screens at baseball parks, on mobile billboards towed by trucks through city streets, as lead-in segments on movies rented for home use, on restaurant menus, on the stall doors in restaurant restrooms, in dentists' offices, in hospitals in doctors' lounges and even doctors' scrub rooms. The advertisements there are for financial services. One does hope that, while scrubbing, the surgeons are thinking of things other than their stock portfolios.

Maybe most of this advertising is audible and visual wallpaper -- there, but not noticed. The increasing desperation of the barrage suggests advertisers' anxieties about diminishing impact. One shudders to think about what they will try next.

Perhaps magazines soon will have pop-up contraptions that grab readers by the lapels and hold on for however long it takes for the average reader to recover from the shock and read the text celebrating the brandy. It will be enough to drive you to drink, which is, come to think about it, the idea.