You see, solo ads have been a proven non-stop stream of targeted traffic to an offer, where you would buy solo ads for pennies on the dollar from a vendor and get relatively high conversion rates. However, Solo ads might be on the steady decline, and within a year or so they may become a thing of the past. You see the industry is changing, evolving and moving forward. Email traffic is becoming a thing of the past due to the ever increasing competition in your recipient's inbox. He or she is inundated with unsolicited spam due to solo ad vendors swapping the same solo ad email offers leading to saturated list emails, thus diminishing a fresh stream of traffic and reducing conversions. And the problem is only made worse by Google consistently and strategically dominating the industry effectively eliminating as much of the competition as possible. That's why we're seeing companies like Aweber and GetResponse's policies getting stricter and stricter and their just banning accounts left and right. As a matter of fact if you have a large email list, let's say about 10 000 then those auto- responders want to see you mail content; otherwise you'll be sent an email from management informing you that your account has been terminated.
It is becoming ever more difficult to get your solo ads to convert at a decent rate and there is also increased risk of auto-responder account termination.
However the death of solo ads will not affect you if you don't use them or rely on them solely for traffic.
It's just a matter of time.