There is no right or wrong. Web push is about sharing content with your audience. That includes already created content for your website, social media, newsletter, PR article, newspaper story, influencer campaign, blog, etc., which gives you an additional "PUSH" for your content marketing. Personalized retargeting is necessary and highly effective in generating re-visits and sales, making PushPanda a perfect additional marketing tool.
For example, if you look at the graphic above, you'll discover many channels. Any content can be additionally shared and sent to your subscribers with PushPanda.