“Indecent Proposal” seems to be the new spring juggernaut.With its ongoing success, how long can the Paramount film hold sway at the box office? Now in its third smash week at the top of the charts — the film that dares to ask how can a woman with more provocative magazine covers than Madonna resist the smell of lucre — its eight-figure weekend gross was $ 10,010,763. And despite a 32% drop in business, the picture’s $ 5,209 average was higher than any other wide release, including and especially the three new ones entering the marketplace last Friday. But to return to the question, the film has a good chance of reigning for another two or three weeks. Timing, in comedy and film scheduling, is everything. “Indecent Proposal” has proven itself as entertainment with broad appeal at a time when niche and genre titles predominate. Until the May 21 opening of Fox’s “Hot Shots! Part Deux,” there are no obvious contenders to the box office crown. The past weekend puts the situation into a more clearly defined perspective. Debuting in second position was New Line’s rappin’ comic thriller “Who’s the Man?” with a three-day gross of $ 4,533,392 from 954 playdates. The film posted averages of $ 4,752, which is a decent take for a film that has a perceived and demonstrated demographic appeal. Three slots down in fifth, Touchstone’s opening of “Indian Summer” registered $ 3,368,711. A considerably more difficult film to sell, the ensemble piece with echoes of “The Big Chill,” had credible $ 3,217 averages from 1,047 excursions. And just behind it in the sixth slot was Orion’s “The Dark Half” which grossed $ 3,250,883. Now, the combination of a Stephen King novel and George Romero’s direction ought to have added up to more than averages of $ 2,080. After all these are potent elements for horror aficionados. There are, of course, other contributing factors — media buys, an orchestrated publicity campaign, etc. — which failed to coalesce for “The Dark Half.” But even had it averaged $ 3,000 per scare, it would remain a film with specific rather than mainstream appeal. “Who’s the Man?” had been tracking strong prior to its opening, so no one should have been surprised by its appeal. Ironically, its audience was not disimilar to that of the Orion picture ‘The Dark Half” and sapped a significant part of the latter film’s anticipated revenue. Which brings us back to timing. If you lose the momentum, it’s unlikely you will ever get it back. “The Dark Half,” in ceding tickets to “Who’s the Man?,” committed an egregious error. When going head to head with a film with comparable demographic appeal, have the patron make your film first choice. No technique is too shameless to use to that end. Secondly, strike while the iron is hot. MGM may have erred in this department with “Benny & Joon.” Last weekend it debuted on 408 screens for returns of $ 3.3 million. This week, with 1,310 playdates, the film did $ 3,804,577. Of course, the studio would have been remiss not to expand quickly but the far more valid question is why didn’t it initially open wider? “Benny & Joon” tracked very well two weeks prior to release. In hindsight “B & J’s” or “Diggstown’s” mini-platforms would have been better suited to “Untamed Heart” and vice versa. The no-campaign award this week goes to SGE’s “How U Like Me Now” which debuted on 11 screens and earned $ 7,370. For those wondering whether a small film entering the marketplace without fanfare or advertising can make it on word-of-mouth… here’s positive results. And the little pic that could is Miramax’s “Like Water for Chocolate” which has earned a tad more than $ 3 million from consistent business since it opened in February. This has to be the year’s quietest, most effective campaign.