"Spider-Man 3" learned that this weekend when it fell 60 percent from its record-breaking debut to take in $60 million, according to studio estimates from box-office trackers Nielsen EDI.

While that kind of drop in ticket sales can be the death knell for some movies, it's not unusual for a summer blockbuster - particularly one that bowed to $151 million, as the film did last weekend. Last year's "Pirates of the Caribbean: Dead Man's Chest", which set the previous record with a $135 million debut, dropped 54 percent in its second weekend.

"The only thing about opening that big is there's bound to be a correction in the market," says Rory Bruer, distribution chief for Sony Pictures, which released "Spider-Man". "We're still where we want to be, which is ahead of the other two" Spider-Man" movies at this point."

"Spider-Man 3"'s overall ticket sales are at $242 million in its second weekend, compared with 2002's "Spider-Man" with $223 million and 2004's "Spider-Man 2" with $225 million.

One ominous sign: "Spider-Man 3" suffered the biggest drop-off of the franchise.

"I would be surprised if "Spider-Man" did more than $350 million," says Gitesh Pandya of BoxOfficeGuru.com. "People aren't loving it the way they did the second one."

And "Spider-Man" will likely be no match for its adversaries: "Shrek the Third" opens Friday, followed a week later by "Pirates of the Caribbean: At World's End". Both movies are expected to be easy No. 1's when they open.

"There's definitely going to be a lot of competition, but we'll hopefully go on to $400 million and beyond," says Bruer. "We think there will be room for all three movies."

Perhaps, but there wasn't much room for the competition this weekend.

The horror film "28 Weeks Later" took second place with $10 million, about $5 million less than expected.

"We're playing to a more adult crowd, so we're hoping we can be the alternative to the big three, which draws more families," says Bert Livingston of 20th Century Fox, which distributed "Weeks". "But it's tough to be heard out there."

Even tougher for the Lindsay Lohan family drama "Georgia Rule", which did only $5.9 million. The Shia LaBeouf horror film "Disturbia "continues its strong run, taking fourth place with $4.8 million and a total of $66.3 million. The comedy "Delta Farce" managed only fifth place and $3.5 million, while the only other newcomer, the Zach Braff comedy "The Ex", was 12th with $1.4 million.

Ticket sales were up 13 percent over the same weekend last year.