I'm number 8 when I use "men's [plus my phrase]" on yahoo.com search, but when I try to search like most normal people would (dropping the appostraphe) I can't even find my site. Does yahoo take the appostraphe so strickly? Google and other search engines seem to treat me rather well if I drop the ' while searching... Any ideas? I really don't wanna have to go back through the site and remove the ' as I feel it dumbs down my site's image.
I've faced this apostrophe issue before, and have been torn over it also.
Yahoo! does seem to take it pretty seriously, but Google also reshuffles results a little when an apostrophe is used, and when it isn't.
How confident are you that the phrase may get significantly more traffic when people search without an apostrophe? On the other hand, how much do you think it might harm conversions without an apostrophe?
Do you have more than one page where the phrase figures significantly into the focus of the page? Would you consider having one page appear one way, and the other page the other way, and test them to see? I don't know if I would try it (I think it dumbs down a site, too), but it might be something to consider.
You could try variants that are grammatically correct as well. For example, you could use 'for men'. It's always surprising how different people search so you may pick up searchers this way that you would not have with men's.
Why not use both variations in your title tag, meta keywords, meta description and in the body text of your page so that both are picked up and regardless of the search term you match - as far as content goes it should not effect you adversly - I don't believe SE's are to strict on grammar and spelling.