2.) Fans (fanatics) of the romantic/comedy genre. As I am rather indifferent to both elements, forgive me if this review may seem a little biased (though I do love There's Something About Mary).
The zest of this film is all about the pursuit of love and ironically the avoidance thereof. The film looks into the social construct if humans are more comfortable with one partner or if we urge to be with more than one; monogamy vs polygamy. Intentionally or not, a study into the aspects of the social sciences is unearthed.
Interestingly enough the resolution to the film finds all three male characters preferring to stay monogamous and firmly in a relationship, even after taking an oath to do otherwise. Does this then suggest the inevitability of leading a monogamous lifestyle; holding fast to the ideals of old of one man, one woman. An ideal that garners a level of sexism as it is often related to concern women more than men, who are portrayed as being the more 'frivolous' gender.
Judging from the film's release poster, picturing the three main actors sitting on a couch with saddened, slightly bemused looks on their faces; one hugging a teddy bear and the other scooping ice cream from a large tub also suggests the emasculation and femininity of the modern man; chasing this pseudo macho concept of the red-blooded male. In actuality they are no different from the needs of their female counterparts. This is certainly the theme director Gormican has chosen to pursue, and it is amusing to watch as the plot begins to unfold and the truth is revealed.