Cabott solid stain

I bidding multiple decks for a few property management company's, like 80 of them..was going to use Cabott solid oil stain, because I like the product and have had good success with it.To help get the job, I figure I'd sweeten the pot with a warranty, so I contacted my Cabott rep and asked how long he'd back up the product. He said 2 summers on vertical application but no warrenty on a deck?. I found that quite surprising, because how can I warranty my craftsmanship, If I can't even warranty the product for at least a year?