Using competitive ad filters to show more relevant links

My Adsense revenues have been declining steadily over the past year or so. I assumed that it was because the economy was forcing advertisers to cut back on advertising, but I wonder now if Adsense just isn’t showing ads that my visitors are interested in. I have a football card site, and a lot of ads were coming up for credit cards, greeting cards, and generic marketplaces such as eBay and overstock.com, instead of dedicated sports card businesses. Most sports card businesses are small, and I suppose they underbid the credit card companies for placement.

Without much to lose, today I looked at a bunch of the Adsense ads on my site, and I entered the domains of the irrelevant businesses in Adsense’s Competitive Ads Filter page. So now most of the businesses appearing at the top should be more interesting to my visitors. It is too early to know if this will help, but I’m curious: how much have other people used this filtering capability, and has it helped?

personnally I didnt use it because I dont have only one site and also because I believe in letting adsense do its job and I do mine. Filtering myself by hand, no thank you. But I understand you may want to do it.