Singular or plural for domain name?

Does adding an "s" to the end of a domain have much difference for seo purposes? For example myniche dot com gets 49k searches, myniches dot com gets 40k. Would adding the "s" cover both terms effectively or is it better to just target one?
Thanks

Personally I'd go for the singular, since 'myniche' is included in both 'myniche' and 'myniches', whereas 'myniches' is not.

I don't think it makes a huge difference. Especially with a difference of 9k in search results. Also, analyse the competition - do the same top ten websites appear for both searches?

I always buy both for my niche i.e niche and niches dot com, then I have them redirect to my main page and I wouldn't even worry about seo'ing the second name, because chances are you will get the traffic by people typing it in wrong, I'm not saying don't bother with it, you can and it will help, I am saying I generally don't bother, because I buy it because people always forget and add the s on the end.

I hope you understand what I am trying to say.

Yep I agree with godmonkee. Why don't you just buy both domains and 301 redirect?

Thanks for the feedback guys. I actually bought both in the end.

sometimes, searchers enter keywords with 's' because they want several results. My opinion is go with the 's'

but that still depends on what keywords you're targetting.