To adjust this setting open up app/code/core/Mage/Media/Model/File/Image.php and go to around line #168. There, modify the number 80 in line $result = imagejpeg($object->getTmpImage(), $object->getFilePath(true), 80); to a higher number. Note that this is a core hack and will most likely be overwritten during a full Magento upgrade.

1. Focus on Upsell Products, Roy Andre Tollefsen, Lead Designer, Silverthemes.com
2. Automation is Not a Subsitute for Outstanding Support
3. Tap Location Online to Drive Offline Sales
4. A/B Split Testing
5. Find Related Forums and Blogs
6. Don’t Be Afraid to Experiment
7. Maximize Your Profit on Every Item Sold
8. More Trust Equals More Revenue
9. Add a Video Play Button
10. See Things From a Customer’s Viewpoint

Read the whole article at Practical Ecommerce:
http://www.practicalecommerce.com/articles/1171-Ten-Great-New-Ecommerce-Ideas-for-July-2009

Main logic for this is we have to get the product list in ascending order by [order_qty]. So to get this type of list we have to apply

$visibility = array(
Mage_Catalog_Model_Product_Visibility::VISIBILITY_BOTH,
Mage_Catalog_Model_Product_Visibility::VISIBILITY_IN_CATALOG
);

$_productCollection = Mage::getResourceModel('reports/product_collection')
->addAttributeToSelect('*')
->addOrderedQty()
->addAttributeToFilter('visibility', $visibility)
->setOrder('ordered_qty', 'desc');

By this way you get the complete list of product order accoding to order quantity for particular product.

Now to display that list in well formated manner you have to loop over the array of product as

<?php foreach($_productCollection as $product): ?>

<?php
$categories = null;
foreach (explode(",", $product->category_ids) as $catId){

//Mage_Catalog_Model_Category
$cat = Mage::getModel('catalog/category')
->setStoreId(Mage::app()->getStore()->getId())
->load($catId);
$catName = $cat->getName();

$catLink = $cat->getUrlPath();
$categories .= '<a href="'.$catLink.'" title="'.$catName.'">'.$catName.'</a>&nbsp;&nbsp;';
}

?>

<?php if($counter <= $totalPerPage): ?>

<?php $productUrl =  $product->getProductUrl() ?>
<div class="best-sellh">
<div class="wraptocenter">
<a href="<?php echo $productUrl ?>" title="View <?php echo $product->name ?>">
<img src="<?php echo $this->helper('catalog/image')->init($product, 'image')->resize(120); ?>" alt="Product image"  class="shadow" rel="black" />
<!--        <img src="images/prodimg01.jpg" alt="chrysler-building" height="150" width="100" class="shadow" rel="black"/>-->
</a>
</div>

<div class="img_txt" >
<span class="yellow-bg-text"><?php echo $product->name ?></span> <?=$catName?><br />
<p class="price_txt">starts from <span class="price_hd"><?php echo Mage::helper('core')->currency($product->price) ?> </span> </p>
</div>

<br class="spacer" /></div>
<!--
<h4><?php echo $product->name ?></h4>
</a>
<small><?php echo $this->__('Total soled quantities') ?>: <?php echo (int)$product->ordered_qty ?></small><br />

<a href="<?php echo $productUrl ?>" title="View <?php echo $product->name ?>">
<img src="<?php echo $this->helper('catalog/image')->init($product, 'image')->resize(120); ?>" alt="Product image"  />
</a> <br />

<?php echo $this->__('Categories: ') ?><?php echo $categories ?>
<p><?php echo $product->short_description ?></p>
-->
<?php endif; $counter++; ?>
<?php endforeach; ?>

In this way you can get the list of best selling product.

How to use this code:

• Just create one phtml file as[highsold.phtml] in category/product directory
• Paste this code in that file [highsold.phtml]
• Now go to layout/cms.xml file and add following line of code

<cms_page>

<reference name="content">

<strong> <block type="catalog/product" name="highsold" as="highsold" template="catalog/product/highsold.phtml" /></strong>
<block type="cms/page" name="cms_page" />
</reference>
</cms_page>

By this way you are creating a block named as highsold

• Now if you want to display the product list on home page.Just go to home.phtml file and ad following lines as<?php echo $this->getChildHtml(‘highsold’) ?>

• next go to admin/cms/manage pages/ and select home pagel. In content text area add following lines as

{{block type="core/template" name="default_home_page" template="cms/default/home.phtml" }}

Now you should see the products perfectly displayed on home page!

<?php echo $this->getLayout()->createBlock('cms/block')->setBlockId('your_cms_block_identifier')->toHtml() ?>