The content network is best when you want to have an awareness campaign. You want to make them know that you exist and have a product they may be interested in. They may not think about it or search for it. Often, they don't even know the product exists.

This often makes such campaigns less profitable as you are just picking their interest and they may come but not buy. It is best when people are searching for a product so I suggest a search campaign more than a content one, but I don't know what the product is.

Of course, you may be doing your campaign all wrong which is what I suspect. Also consider that maybe the landing page does a poor converting job.

The offer is blendtec.com, the ad size was 300x250 , promoted through google content work in chow.com . Lots of clicks from the visitors but zero conversions why?

I'm not sure if promoting blenders, especially such expensive ones, is something I'd use the content network for. I'm guessing you are using keywords and probably simply "blender", right?

Why not have other image sizes? And text ads? Which landing page are you using? That would affect your conversions. But mainly, for $500 blenders (one at $1500), you better convince me that's it's the best blenders ever and will do more than blend. I just don't see that and it's not something I would buy, not at that price.

How many clicks is "lots"?

Basically, I would have a search campaign and only on the brand. Those knowing the brand would know they are expensive. A very targeted display campaign may work. You'd have to target sites whose visitors would be likely interested in these (chefs? restaurants?).

Chow.com's users may be the types to need a blender. But are they the kind to "fork" over $500 for one? You can test and see but my initial reaction is no.

I think you should concentrate on the commercial side and promote the smoothie machines and dispensers.

Google Search Ads are better instead of the display network for the type of offer you are promoting. The display network (as LWM ) said, for generating awareness.

I don't know if it is appropriate to post digitalpoint forum links here but some guy claims that he is making nice money promoting CJ products with PPC. Search in that forum if you like.