Is there anyway I can make some ad display at random more often than others

Hi,
I have a table of advertisement with expiry date and location. Currently, I display ads at random base on user’s location.

In the near future, I want to add tier system in to my ad sale. It means the first tier ad should be displayed more often than the second tier.

Is there anyway I can do this?

Thank you,

 

yes definitely, post what you have started.

adding some sort of percentage to each tier will work.

 

Thank you very much for your response. I thought there was hopeless. Here's the thing I've been doing so far:
Creating a table:

$mysqli->query("CREATE TABLE `ads` (
  `id` INT NOT NULL AUTO_INCREMENT,
  `uid` INT NOT NULL,
  `txt` TEXT NOT NULL,
  `date` DATE NOT NULL default '0000-00-00',
  `img` VARCHAR( 120 ) NOT NULL,
  `location` VARCHAR( 75 ) NOT NULL,
  `expiry` DATE NOT NULL default '0000-00-00',
PRIMARY KEY ( `id` ),
UNIQUE (
  `id`
  )
) ENGINE = INNODB CHARACTER SET UTF8 COLLATE utf8_general_ci
")
or die("DB error!");

Code (markup):

Random with PHP:

SELECT id, uid, img, location, expiry
FROM ads
WHERE location = '$location' AND CURDATE() < expiry AND RAND()<(SELECT ((1/COUNT(*))*10) FROM ads)
ORDER BY RAND()
LIMIT 1

Code (markup):

I've tried to google what you've suggested. No luck so far...

 

oh you used query, not in a single query though but in a procedure
ie.
given 3 types of ads
1st - 70%
2nd - 20%
3rd - 10%

pseudo code

Initialize ad_number to 1
Initialize random number in between 1-100 to n variable
if n in between 1-70
return 1st tier
else n in between 71-90
return 2nd tier
else n in between 91-100
return 3rd tier
else
return null

 

Thank you. I'd try it.