Everything Google has said that the bot does, plus a knowledge of coding. They aren't using a LYNX style browser to render javascript and determine the position of ads on pages. They have to be using a headless type of actual browser for that - and it's a safe bet they aren't using firefox or IE or safari.
They aren't telling us how Googlebot is coded, but it's pretty easy to deduce.
Just because they will index it doesn't mean it won't harm your ability to rank for that text.
Google bot is a headless vesion of chrome - so while they can see that stuff, they also know when stuff isn't "visible" to the user and treat it accordingly.
The problem with tests like this is that you either need to test with site: or with made up terms - but the algorithm isn't static - it changes based on the corpus of relevant results. (e.g. if there's only 3 relevant results, then they won't apply spam penalties or panda weights, etc)
When you have such a small scale test, the corpus of results is always small - so it's not accurate.
I'm confident that if you tried these techniques on a site with content currently ranking in a highly competitive area, then changed it to one of these, your rankings would fall.
Make the SEO play here. Create a static link for each button with the text that I type in, so I can link people right to it. Then, with proper title and headings, etc you can probably get some traffic for "random long tail term button"
The solution isn't to make linking illegal - it's for Google to stop the penalizing and just simply not count the links they don't like. Penalize for on-site stuff, just ignore the off site stuff.
I realize they want to take away the incentive for spammers, but let's shift the burden of finding a better way to do that onto them instead of changing the laws about how the web works.
This takes us down a very slippery slope. Linking, is not illegal and I think we can all agree that the web would be ruined if simply adding a link to a site you own or control were made illegal.
So that raises the question: How do you determine what's a good link or a bad link? Pretty soon you'd have people arrested for linking to somebody's site from a news article or to/from sites like ripoffreport.
I still use Lijit for their "backup ads" feature. Basically, I monitor the CPMs I'm getting from other networks, then set my floor CPM in Lijit to that number. That way, I get about 30% fill with Lijit - but it's guaranteed to be at a higher CPM than the other network. Chaining them together works really well - you just need to do it asynchronously so that it doesn't impact load times.
so, I realize this might be seen as spam, but I am always trying out adsense alternatives and regularly maintain a list of the ones I'm trying out. http://www.dotcult.com/best-adsense-alternatives/
TLDR: casale, Lijit, technorati are working best for me.
it's really quite simple. The pages that get more +1s and likes and comments and whatever metric you want are the ones that are good. The ones that are good also get more links and other signals that are used in algorithms. The hidden middle-factor here is "quality."
That, or simply: "the pages that have more +1s have them because they ranked and got more traffic. e.g. nobody's +1ing pages that they can't find."