Best Domain Type

Whats better to go for say if my target keyword is big dog is www.bigdog.com or www.bigdogs.com better with the s or not, or doesn't it matter?

 

it can matter.

what are searchers more likely to "search for?" singular or plural?

 

I would use hyphens , big-dogs.com , SE's see hyphens as spaces.

You might also want to register bigdogs.com and 301 it to big-dogs.com.

 

yeah as eiso said, why don't you register both and redirect one to the other

 

What I mean is, is plural better than singular?

would sausages.com still be as good as sausage.com for the keyword sausage..???

 

If you have the option, get; bigdogs.com, bigdog.com and big-dog.com. Usually, it is better to get the plural version of a keyword domain name since this will show up for both plural and singular keyword searches. If you go for the singular version then plural searches will get missed.

Remember, this is for keyword domains. If the domain is for a brandable version then you really want to grab the plural, singular and the hyphenated. Also, if your intention is primarily type-in traffic, the hyphenated domain is the least best option.

If your intention is resale of the domain, then the best version is usually (though not always) the plural.

 

It depends on how you will develop it.
If you wanna brandize the term "big dog", then you should go for a singular forum.
If your site talks about "big" dogs in general, then go for a plural form.