I have a content blog that I want to show different widgets(ads and links) and different content based on if a user comes to my site either organically, from native, from email, from social, etc. I was wondering what method would be the best way to go about this and if any effect it has on SEO. I was thinking of using PHP server functions to detect incoming uri's for a string in the uri. But I figured everything would still be seen by google bots, so it would not necessarily be cloaking. Is this there a better way I should be going about this? or for performance/code integrity/SEO is there a best practice way to do this? I've only been web-dev for a year and relatively new to bhw and seo in general.