I do alot of Ebay-ing for my coupons.....my Mom and I go in 1/2 and trade coupons
I know my store well.....and the things that go on sale regularly.
I don't toss any coupons til they expire.
and I also watch for lots of wyb(when you buy)coupons also......these usually result in free products when I buy something I normally get anyway.
I also watch the store closely for coupons ON items.Our store does a thing where they will put coupons on things for other things in the store also.....last week they had $1 off coffee coupons on bacon.......the coffee was on sale so I got the coffee for like 1.50
I think people have a hang up with Ebaying for coupons cause you pay for them......I rarely have to pay more than 1.50 for 20 coupons......and my saving far exceed the cost of them.

I buy them on Tuesday evening and my ad doesn't start til Thurs so I have plenty of time for the coupons to get here also.
I'm also lucky cause my store still doubles coupons.