Yes, I think it makes the couple look cheap. If they can't afford the hoopla, they should scale the wedding back to match their means. The end result is that they are still married.
What's next? Baby shower sponsored by Kid's World?
Is the word of mouth going to spread about brand X store sponsoring the wedding, or is it going to be, "can you believe that Bill and Jane had brand X store pay for their wedding cake?"
Is it truly going to raise revenue for brand x store, or is it only going to make more couples go to the store to get help for their special day, too?
One of the tackiest things I ever got at a shower was a favor from Mary Kay with 2 sample lotions in it. That didn't make it tacky... the fact that there was a card from the MK distributor made it tacky.