Are you thinking about the short term or the long term? Some cpa marketers might have plans for the future and building up the mailing lists might be a part of their business plans.
Can you come up with good domain names and ideas for websites? This might be another part of your portfolio. The internet domain names and websites might be another source of value.
It might be simple to create the internet websites that could turn into potential sources of traffic in the future. Building up the sites over time might be a part of your bigger plans.
Are you going to build up your sites using content management software programs like wordpress? The cpa marketers might not have the development skills to build sites from the ground up. The cms software tools like wordpress could be the quick solution for setting up the niche sites and getting them ready for the online visitors.
The cost per action offers might come and go, but who knows what the internet domain names will turn into. The idea of adding in a mailing list could open up additional doors.