My First Sticky; setting targets

I signed up for the $110 sticky bonus (100% deposit match + 10% Neteller bonus, 12x playthrough) at Acropolis last night, and started playing. For an explanation of what "sticky" means, Acropolis has the clearest explanation I've seen anywhere.

I've been torn about what strategy to use -- bet it all then grind, bet big chunks then grind, or grind then bet it all -- but finally decided on the middle ground. By betting big chunks, then grinding away once I hit my target, I'd be able to either bust out quickly, or else have minimal WR remaining once I hit the target. (More on setting targets below.)

At least, that's the theory. I was too lucky. Starting with $220, I started by betting $25 a hand at Blackjack Surrender. I hit my target of $400 in about 20 hands, sitting at about $420. I was really surprised, since I'd expected to lose it all. I'd met only $500 of the $2640 WR, so it was time to start grinding away. Soon, at about $800 in WR, my account was down to $360, so I figured I'd do a couple more big bets, $25 a pop. About 15 hands later, I was back up to about $425, after a drop to around $325.

(Side note: on one big hand I was dealt 8-3 versus the dealer's 6. It's a clear double down situation, which I did and won. The words "Won $100" on the screen came as quite an adrenaline rush, though.)

Time to keep grinding away. I should have it completed tonight.

So why was my target $400? In the bonusbug.com forums, there's two popular formulas. The first was written by someone with a small bankroll trying to play conservatively:

Target = Bonus + [{ Sqrt (Entire Bankroll * Bonus) } / 2]

So the target should be the $100 bonus, plus half the square root of (my $800 bankroll times the bonus). That's about $242. After withdrawing the $100 sticky, that'd leave me +$142. This didn't seem like a big enough target.

The same person who wrote the first formula recanted it once he had a bigger bankroll and a higher risk tolerance, and came up with this revised formula:

Target = 2/3 Bonus + Sqrt(2 * Entire Bankroll * Bonus)

So my target with this formula would be $67 + Sqrt(160000), or $467. After withdrawing the $100 sticky, that'd leave me +$367. That seemed a bit too high, a bit too risky. $400 sounded about right, though.