prefix suffix vs plural "s" in term of SEO

I think you should use compostingbucket.com this type of domain because it will be very helpful to get high rank in SERPs, If you thinking targeting "composting bucket" keyword for your site.

Personal preference as I have never actually done any testing, but I prefer suffixes over prefixes. With e suffix, my main keyword remains up front in the domain name, which might not affect SERPS but might add the 'human' factor of making it more noticable.

When it comes to suffixes, I like those that make a plural. I also like those that are 'human engineered' to entice searchers, although some might regard this as dishonest.

Example:
compostingbucketstore.com

Gives you the plural and also implies that you're a store. I bit misleading, so if it bothers you conscience, dont' so it.

More:
compostingbucketsite.com
compostingbucketshop.com
compostingbucketsale.com
compostingbucketspecial.com

Or no plural forming suffixes
compostingbucketcoupons.com
compostingbucketsreviewed.com
compostingbucketreview.com

I've found searchers seem to especially like coupons since that implies savings. What I do on these sites is list the product and then at the bottom put something along the lines of

There are no current coupons for XXXXX
Please check Amazon for best price.

With Amazon being the affiliate link.

If you type in a search using plural...for example reviews rather than review, google will still bold review in the search results. And vice versa.

Why not consider an exact match .net or .org? Depending on the content, an exact-match-top-level-domain-extension might add extra seo value.

Org's don't seem to work as well for product words. I think they are best for information sites, like "what is" or "how to" sites. People have different associations they form when they see an org as opposed to a com or net.

I agree with Paul. Don't get hung up on whether the keyword is in the domain, or plural, or has a prefix or suffix. Do your seo right, you'll have all the traffic you need.

i have done alot of keyword research and i anaylize keyword by market samurai, i saw keyword with exact match in domain org,net,com rank very well, super well, with only few backlink plus all on page is fully optimize

so if i going to beat it, i understand i need to put additional character in domain because com,org,net all gone . so what is best option to add additional character

prefix
suffix
article ---> the, a
plural ---> s, es
other wordl--> all ----> allkeyword.com

as what i understood, the rule is

less character
suffix batter than prefix because to let SE read keyword well

but what about this, let say for keyword "cast iron waffle" . we may choose

1. castironwaffles.com or for cetain keyword add es
2 .thecastironwaffle.com
3. castironwaffleall.com
4. mycastironwaffle.com
5. castironwaffleshop.com
6. castironwaffleinfo.coom

what in my head thinking is,

the number of additional character
prefix or suffix
relevancy additional word ---> all
article, a or the , i think this does not make sense

i thin google give some relevancy weight, to other word maybe 3 character have any related with the main word ( look at google wonder wheel).

which will you prefer ,people