I remember a while back I had read somewhere (a Reddit thread perhaps) where the Cap1 portal axed a guy’s account because he had amassed too many rewards and they just assumed he was abusing them. Anyway, I had been axed by them before a few times. The reason I think I was axed in the past was because they had detected a duplicate account (maybe I had re-used the same phone number.) I don’t think it was abuse per se. And it’s not just me that have been banned from them.
Anyway, I don’t think they linked my accounts by IP since some of my newer accounts are still alive. The accounts that they got had a significant amount of pending cashback and/or total cashback history. I think it’s safe to assume that once you get close to $10K of total cashback, you may want to move on to a new account. Hell, you may want to move on earlier than that (maybe around $5K even.)
Going forward, I think I’ll spread out my purchases over a ton of Cap1 accounts. The only downside is that while the money is payable after 30 days, you can’t cash out a new account until 90 days. But this will mitigate the risk of putting all of your eggs in a few baskets. I’m considering doing VPN for each account as well because I’m sure that’s how they’ll detect duplicate accounts in the future.