I’ve just recently run into this situation and wanted to share some tips with you on how an e-commerce store can best use Google AdWords.
First, it is important that if you are using a third party shopping cart that you understand that you really must create shopping category pages on your own front end website under your domain name if you will be promoting your product categories using Google AdWords.
Here’s an example, let’s say your domain was www.ILoveShopping.com. Your main domain only had a few pages residing there, your about us page, contact us page, and your site home page. When someone clicked your “buy dog toys” category link in your website navigation they were sent to bigstore.giantserver.com/ILoveShoppingcom/dog-toys-for-sale.aspx.
For AdWords you could not point to this category page in your ads as the destination URL if you wanted your display URL to be www.ILoveShopping.com. You would instead have to have your Display URL be bigstore.giantserver.com/ILoveShoppingcom and the destination URL be bigstore.giantserver.com/ILoveShoppingcom/dog-toys-for-sale.aspx – right?
Well, at least this is supposed to be how it works, but just recently Google would not even allow an advertiser use this format. It may be the max URL count for the destination URL is over the 1024 that are allowed or that the shopping server really does not exist and is a redirect page set at the store server level. And besides that who wants to be doing AdWords and have customers lose confidence when they see a weird display URL like: bigstore.giantserver.com/ILoveShoppingcom instead of ILoveShopping.com?
So, without being able to link to the category page suddenly your quality score on dog toys slips to 7 or even 5 and you start paying a chunk of cash to promote this popular category for your store.
If this is your situation, before you start promoting your store on AdWords you really need to address this by creating a category page that is keyword dense and lists your products by name or categories and then from there links to the store. Not only will this help with your AdWords quality score, it sidesteps the Display/Destination URL problem mentioned above, increases conversions, and will even help your main front-end site place organically as now your parent domain has new keyword dense relevant content to what you are selling.
If you have tons of products and say nah, I am not going to do this, you may want to consider creating a landing page for the category you are promoting on your main website that then showcases only your top sellers and has a prominent link to the complete category page in the third part store. Whatever your plan, to send the customer for a specific category to your home page where there is no specific content on this category or products to buy is wrong and a fails miserably when it comes to building a great quality score and increasing conversion.