If you have maxed out your competitive ad filter, you are in luck, because AdSense has increased the number of filters for publishers up to 500.
Here is the thread at WebmasterWorld from AdSenseAdvisor
Check your account. We have more than doubled your number of filters (to 500).
Please don’t go crazy with this. The reason we’re not announcing it on the blog is that we don’t want to overload our system with everyone filling their filters to capacity at once.
Huge thanks go to the awesome engineering team that implemented this for us (I’m an AdSense publisher, too, after all).
Please feel free to leave love letters to our engineers below.
Now, don’t go nuts and only add them as you need them. But before you do go crazy adding URLs, don’t forget that when you block an advertiser, it only means ads worth *less* money will show in its place. So if you plan to block advertisers because you think their ads are low paying, you are only going to end up making LESS.
More on the competitive ad filter is here.
Note: This blog post was corrupted in the database and was reposted, please see archive.org for original comments.