In regards to the GS purchase and how everyone is approaching it:
Maybe I'm lucky, but I do it very differently than others on here have done or suggested (I don't mean that in a bad way, just that my approach is different). I walk in with head up, smiling, and yell hello to the young guy, or girl at the counter, who yelled hello to me when I came in. I'm in a great mood. They ask if they can help me, and I say "Nope. Just grabbing one of these eBay cards." Walk right up to the counter, and tell them "I got $140 on these electronic gift cards that I printed out. I'm going to load all of it on to this one eBay card. I forgot my rewards card, but I wrote the number on that sheet there."
Commence small talk as they are rung up (after confirming my rewards card for 2%). Wish the employee well and hope it doesn't rain on them too hard, and I'm out the door.
Now, my write-up above makes it sound like I'm coming off cocky and arrogant. I assure you, that's not what I mean. I'm very personable and outgoing. But, there's a few mannerisms that are important, in my opinion. First, I didn't ask if it could be done. I believe that a question like that immediately sends the employee to question whether or not it could/should be processed. I casually make it seem like I've done it before and it's expected to go through just like any other transaction, because it is. Second, I don't ask if gift card purchases are excluded from the rewards program. That gets them thinking that maybe something fishy is going on. Third, I appeal to their "expert" status and ask them about a game (in my case, Disney Infinity for my kids) and would like their knowledge and advice.
I casually say that this is what I'm getting, and here's how I'm paying for it. Part of me really believes that normalizing the transaction goes a long way.
Again, maybe I'm just lucky, but as new as I am to this, but I've successfully bought $455 in eBay GC from two different GS and 3 different employees. Nobody batted an eye. Most were more focused on the conversation we were having, instead of deciding whether it 'could" be done. Two employees were excited about the amount of rewards I was getting.
Sorry for the long post, but I'm a big believer in the fact that we can influence how people respond to us, just by what we say and how we say it.