Couple of things you might want to check into:
Your page title, meta description and meta keywords tags are too long. Try to keep your page title shorter than 66 characters, your description less than 160 and between 4 and 8 distinct keywords per page.
Don't use your home page to list every possible search phrase users might use to find your site. Remember that you can and should modify every single page, including product display pages to make them as focused and relevant as possible.
That's where you'll get the most bang for your buck.
HTML Code:
<title>Promotional Products & Merchandise from Sourcing Planet</title>
<meta name="description" content="Over 75,000 custom promotional products and merchandise ideas from suppliers, wholesalers and manufacturers around the world." />
<meta name="keywords" content="custom, imprinted, promotional, products, items, merchandise, ideas, gifts" />
In FireFox, your "Item Types" page is breaking out of the page background and your "Tools & Services" links are out of place in the lower right column.
You've used <h1> tags and that's good, but make sure it's not just an exact copy of your page title. Use it to target a similar but different permutation of one of your targeted keyphrases, on product pages, you might want it to consist of the product name.
Google lists a grand total of 4 unfiltered inbound links to your home page. You definitely need to work on that.
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