<prompt> tafsiri zifuatazo kutoka kwa swahili hadi kiingereza.ingawa kiwango cha ubadilishaji wa matangazo ya bidhaa ya amazon kilipungua kutoka q1 2011 hadi q1 2012, utitiri wa wafanyabiashara walioorodhesha programu hiyo, kuongeza ushindani kati yao ni sababu kubwa ya kupungua kwa wongofu.  <response>: although the conversion rate for amazon product ads decreased from q1 2011 to q1 2012, the influx of merchants listing on the program, increasing competition with one another is most likely the cause for the decrease in conversions. 