Should Cost-Per-Click (CPC) AdSense Earners Worries about The Google's New Cost-Per-Action (CPA) Programs?

I finally understand how the Google's CPA programs will work on AdSense publishers after reading the latest announcement of their launch of AdSense Referrals 2.0. The CPA program will only affect CPC AdSense earners slightly in the future because the CPA program has placed under the referral section. AdSense publishers can choose not to display Google CPA ads and continue enjoying pay-per-click earning.

Advertisers like CPA advertising most because they pay for the ads only when a sale or other actions specified by them occur. But unfortunately, they wouldn't get the traffic they expected (possibly getting little traffic only) from CPA advertising since AdSense publishers can choose not to display their ads and send visitors to them. So most AdSense publishers in niches that work poor in CPA programs will not use the CPA ads, they want to continue earning steady income with Adsense CPC ads. And thus advertisers in those niches who want to gain consistent paid traffic from Google still have to stick with CPC advertising.