SEO implications of using different content with the same URL for campaign purposes

Question

I'm assessing the feasibility of serving up slightly different content based on the campaign ad that is clicked on. In many aspects, this will be similar in approach to serving up different languages or adaptive design for mobile, with different content having the same URL. However, I can't find any overt indications that Google actually supports this kind of behaviour, since it isn't based on language, nor user agent. Would such an approach be detrimental to the overall SEO results?

I'll add that I'm aware that it would be far more straightforward to simply create different URLs with the different content; I'm just investigating whether this would be a viable option.

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EDIT: It is for a landing page. It's not so much for SEO purposes as to simply tailor the content to the user's interests (as demonstrated by the particular link they click on to get to the page itself). As @lucgenti points out it's similar in approach to a multivariate test, except it would be ongoing, not just for the duration of the test.

Answer 1

The same question is legitimate in case of multivariate tests.

Follow this guide: http://searchengineland.com/googles-seo-guide-on-ab-multivariate-testing-130093

The best advice of all is to put a canonical to a page with static content.

Answer 2

Googlebot will only be able to see one version of your page. If the content uses different keywords, Google will only be able to rank one set of keywords for that URL.

As long as you show Googlebot and visitors from the Google search engine the same content, Google won't penalize your site for cloaking.

Landing pages for ad campaigns, aren't usually good at drawing in search engine traffic anyway. You could noindex that page. Then Google would ignore it, you wouldn't get SEO traffic to that page, and there would be no possibility that it would hurt your site from an SEO standpoint.