Lets say you cloak to block users from paid content.  Would that be ethical?  What are the alternatives besides Google First Click Free.

It is a difficult question to answer without seeing the specifics, but - First Click free/ or first five clicks free would be my preference (as this is the option provided by Google and provides the opportunity to rank on all of your paid content).

But - if implementation is difficult you could consider providing the first 500 words (say for example) of each paid article. to both search engines and non-logged-in users. members could of course view all the content.

It would not be "ethical" to cloak to block users from paid content but allow search engnies in without allowing free users some mechanism to view at least a significant portion of the content  so they can review before they purchase.

Remeber that free users may also check the google cached version to see your content (unless you have noarchive REP set)

Search engines have matured tremondously over the years, and the ability to catch unethical means of promoting websites, and using unfair means of ranking high in search results will not go unnoticed. All major search engines hate any unethical use of SEO strategies to gain unfair advantage in ranking high in search results. It may take a little while, but eventually all unethical tactics to gain SEO advantage will be eventually exposed, and accordingly penalized.

Nice sentiment @uptrg and it's what I've been saying for years. However, it's not actually true at the moment. Spamming the search engines works very nicely and in fact may be the only way to gain traction in competitive markets these days.

Sad, but true.