The timing of instant wins is pre-determined and they are randomly seeded throughout the term of the sweep. Let me repeat that so's there's no confusion - timing of instant wins is pre-determined and randomly seeded throughout the term of the sweep.
The first person to enter on or after the pre-determined winning time is the winner.
You're just as likely to win at 9PM as you are at 3AM.
If there are 10 prizes on a 30 day sweep, they'll be randomly seeded over the 30 day time frame. Random means random. Any possible combination of dates and times that add up to 10 wins in 30 days is possible.
There are exceptions, so read the rules carefully. There was a recent sweep for a rather large amount of cash. In the rules, it was stated that the winning times would be in fractions of a second. If you were the first to enter after the winning time you didn't win. You won only if you entered exactly on the winning time. Don't quote me, but I think the winning time was a tenth of a second. I don't think the sponsor expected to have anyone win.
The games that are occasionally part of instant win sweeps have absolutely no bearing on winning. They are there for entertainment purposes only. I always skip the games If given a choice, and move on to the next sweep.
Finally, the sponsors are free to do anything they please with the rules as long as it's legal. So, it's possible that there could be rare exceptions to the above. The sponsor puts up the prize(s) and the promoter organizes, promotes, writes the rules and runs the sweep in accordance with direction from the sponsor(s). Occasionally the sponsor and promoter are the same.
I started sweeping on another site almost 20 years ago. I've won $5,000 from Burger King on an instant and a Lenovo Laptop on a daily. My wife just won a $1,000 Laptop (Ultrabook) on a monthly. The sweep she won is still active and there are still two entry periods left. Here it is:
Microsoft.Com - Discovered Sweepstakes (
https://microsoft.promo.eprize.com/intelsweeps/:b=firefox15/ ) Timing: The Sweepstakes begins on September 5, 2012 at 12:00 a.m. Eastern Time("ET") and ends on January 31, 2013.
Prizes: FIVE (5) MONTHLY PRIZES (one (1) per Monthly Entry Period): An Intel Laptop (model determined by Sponsor in its sole discretion). Approximate Retail Value: $1,000.
The point is that wins are happening on all of the different entry types. Don't get hung up on instant wins. Focus on the prizes you want from all sources, and don’t get caught up in the immediate gratification of instant wins.
I lived in Calif. for a number of years. I didn't find that to be a disadvantage. The US population is heavier in the eastern time zones, so it stands to reason that you'd see more winners from there. It doesn't give them an advantage, it just means you'll see more winners from areas where the population is larger and more people are entering.
I've won so many times, from so many different types of sweeps over the years that I can't remember 'em all - or perhaps it's altzheimers, eh?
Welcome aboard & good luck
PS: Please excuse any mistakes since spell check has disappeared from the new Forum.
I've been sweeping for 2 months now, and I am never lucky with the Instant Wins. I live in California, so for most, I can't start reentering at 9PM at night. I have changed the times I do my instant win,late at night, early in the morning, mid day, but still no wins. I play every day and always tell myself I can win 
