Hmmm, I just tried to login to Adzerk using my account that I registered back in March 2013. It doesn't work anymore. I can still enter my username/password, but nothing happens. I can even reset the password.<p>Perhaps it's because when I signed up, ad serving was claimed to be free for up to 100 million impressions per month. That changed: <a href="http://adzerk.com/blog/2014/01/an-update-about-new-free-adzerk-accounts" rel="nofollow">http://adzerk.com/blog/2014/01/an-update-about-new-free-adze...</a><p>"Certainly! If you signed up for an account before January 6th 2014 and were actively serving ads, you can still serve as many impressions as you want for free up to 100 million impressions per month. However, to contact Adzerk support after your 30-day trial ends, you must purchase a support app in the Marketplace."<p>So I guess they disabled my account because I wasn't actively serving ads? It would have been nice if I had received some kind of notification at least.