Seems like the article is only showing half the story.
Costs are going up which means increased competition. Increased competition will mean your ads are running against more competitors. Reason for fall in click-throughs could be under-optimized ad's losing out to competition's ads.
As for conversions. Looking at the table plan site I feel overwhelmed. If this is where the ad's are taking users I think it is fairly obvious why sales are dropping off.
I don't think Adwords can be blamed for the profitability of a product.
This isn't to say Adwords isn't declining in value for site owners. To make this claim though you would need information from lots of sectors from lots of site owners.
Costs are going up which means increased competition. Increased competition will mean your ads are running against more competitors. Reason for fall in click-throughs could be under-optimized ad's losing out to competition's ads.
As for conversions. Looking at the table plan site I feel overwhelmed. If this is where the ad's are taking users I think it is fairly obvious why sales are dropping off.
I don't think Adwords can be blamed for the profitability of a product.
This isn't to say Adwords isn't declining in value for site owners. To make this claim though you would need information from lots of sectors from lots of site owners.