There's a sort of "scam" where advantage players uses Netellers Loyalty points scheme to earn more money. I believe Neteller's program works so that you get points per transaction, so the more you move around, the more points you get. I think the points can then be traded for money, kind of like "rake back" in poker.
So if you combine that with advantage play you can earn quite a lot more.
If a casino gets hit by a "ring" with lots of fake identities and good proxies, a quick response could be to throw something like that into the T&Cs and get the ring to move to another casino, there are a few others out there.
This could have been what happened to Ladbrokes. It's out there at least
Neteller only ran these promos for short periods of time, and particular merchants didn't count. All Ladbrokes had to do was get deposits to Ladbrokes excluded from all such promotions just as other merchants have done. This would have moved this scam to another casino WITHOUT penalising regular players who were depositing to play, not move large sums around.
The fact that Ladbrokes never did this, and never lifted the "temporary" restriction from the terms, means that this is not the reason, or at least not the main reason. Whatever reason they have, it cannot be dealt with by opting out of such Neteller promos. They also included Moneybookers, so it looks like they want rid of eWallet users altogether, not just those who take advantage of such promos.
Neteller also have a term that states that any member found to be moving money in and out of merchants with no real intent to play will have their reward points docked, and they will be excluded from all such promos in future. All it would take is a complaint to Neteller from Ladbrokes, and not only will the scammers be moved on, they will be stopped from doing it anywhere else.
To me, it looks like Ladbrokes are arrogant, and refuse to use the channels Neteller have set up for dealing with this problem after merchants in general complained about abuses of such promotions. Ladbrokes are also excluding potential VIP high rollers, as unlike Neteller, it is hard, if not impossible, to deposit the required £7000 per month needed to qualify for consideration for the VIP program because the banks will repeatedly block and check such transactions. I had this problem with deposits of £200, let alone £2000, with one card blocking every other deposit, and I then had to wait for "office hours" to pass a fraud check and unblock the card. I was told there was no way to "whitelist" merchants in order to prevent such problems.
With the 1% cashback being offered by Neteller when they ran these events, it would need some pretty blatant action by the player in order to profit, as 1% can easily be eaten up just by wagering the deposit 1x.
Credit cards ALSO offered such cashback schemes, yet this didn't seem to bother Ladbrokes. With credit cards, it was a permanent cashback, not one running just for a month or two. I was getting 1% cashback on my Barclaycard casino deposits for YEARS until Barclays eventually ditched the scheme. I was using the card in preference to Neteller because of this.