Hey Jeff - are you willing to back your statement up with a "It's 25 servings or you can kick me in the sack" guarantee?
Sorry - but YOU might get 25 servings but that COMPLETELY depends on the size of the serving & how full the tray is. As I am guessing Phrasty is asking in relation to working out quantities for a commercial gig - it is not as simple as saying "25" or "10" or "1000". Without knowing how large the serving size & how full the tray (a 1/2 1/2 tray will serve less than a 3/4 1/2 tray or a full 1/2 tray) the question needs to be answered as "I use a (insert ounces) serving from a (insert how full the tray) that is (insert how deep the 1/2 tray)" Anything else risks giving advice that will ultimately screw the estimate for the OPer.
So - to correct my answer:
We use an 8oz serving from a mostly full 1/2 tray that is 2 1/2 inches deep and get 10 - 12 servings.
Cha Cha Hut BBQ : 43311 Route 28 (corner of Route 28 & County Road 38: Arkville, NY : chachahut.com
Backwoods Pro Jr.
busted Backwoods Fatboy
Weber 22.5 Kettle
some stainless wood fired thing