I used to enter the dv lottery every year but I didn't win, why?

DV-2010 is a lottery. You can't be a winner unless you have luck. At the KCC, Computer selects the winners randomly from the submitted entries.

There are people who won lottery twice. The first year, their case number was high so that they couldn’t get the interview, in the next year lottery too they won when they applied.

There are families where husband and wife both won the DV Lottery in the same year.

So it is totally luck.

First of all read the instruction carefully.
You can enter your name as primary applicant only once.
Don't enter your name as primary applicant more than once. If you enter the lottery more than once, they will reject all your entries without notice to you.
So don't think you are participating in the lottery when you have submitted 2, 3, 4 entries. All your entries will be disqualified.
Only apply once, then only your entry will be included into the lottery.

Does your photo meet the required standard?

The program will accept your photo if the size is correct. But it will be disqualified later with out notice, if it is out of focus or don't meet the other specified requirements.

So to enter in to the lottery, send your correct photo file.

More photo instruction can be found here.Click the link.

Use correct postal address which is the normal mail address for you, where you have smooth mail service. Other wise your winning notification may not reach you. If your country postal service is not reliable for your home address, you can use a friend's address or a relative's address in another town or in another country.

Good Luck to you.