THe problem is, its all based on luck in general. You should 100% make sure you have the right table, the wrong table with a single option different means you could be essentially losing one hand everytime when you should maybe be winning it 2/3 of the time. Remember also in general the trend seems to be, the doubling up options are where you make money, the single bets will almost always have a house bet. Everyone I've done so far stats dictate that single bets i'm always between 10-25% down on, but double bets i'm normally 5-20% up on which normally evens out. So i might lose 50 double bets, but win 65, while at the same time winning 500 singles, but losing 600. It evens up the losese dramatically, but on one day the doubles are all going wrong you make a big loss really.
ALso, 99% of the casino's do NOT allow single deck blackjack to count against the wagering requirement so double check what you're doing asap. single deck has around a 0.1-0.15% house edge, tiny in the end, but the lower the betting requirement, the less evened out the results will be. multideck(often 6 it seems on most casino's) still only gets up to a house edge of 0.6% at the worst but thats assuming you play enough hands and with perfect stratagy and maybe a tiny bit of luck.
I had two very bad days and still made a profit. Bet365 i ended up losing the entire bonus and 10% deposit, so down £10. Golden palace was going so well, £7000 into the 8000 requirement i was up to £475(£100 deposit, 300 bonus 75 winnings) and ended up withdrawing at.............. wait for it.............. £246 total. Never seen such a horrendously bad streak, lost almost every double and I kept hitting doubles, software screwing with me? honestly couldn't say, feels like it. But even so thats £146 profit, though for a while there I was looking at a £350ish profit so was a bit of a kick in the teeth
Intercasino £45 deposit £45 bonus, down to £2 in 30 mins of pure bad luck, i quit and was really smegged off at that point, chances of me making that back now, next to none
So total profit is only £90 from a possible £450(excluding winnings), and that would only have an expected value after betting of around £300. But I would say thats about as bad luck a run as you can have, hopefully I can go for another few casino's with my bad luck allotment all gone and bag close to the full bonus.
Not tried VC yet, but bear in mind that some casino's are INCREDIBLY SLOW per hand and some are massively faster, most have the faster software. Intercasino was abysmally slow compared to Golden Palace, also remember after 1-2 thousand hands from the very start you automatically know what 99% of the choices are and can send off hands in seconds easily.
From what I can tell casibot which i used a little, made my computer very laggy(using more cores than it should maybe, need to check) and uses your mouse to make real movements in the software so using mouse pauses it for 5-10 seconds meaning you really need to run it on a computer you aren't using.