With PHP its not that difficult to detect the google spider. problem:If i'm lazy to update a website , but i do want to show google something new once in a while so it thinks my website is being updated. solution:I could show some content from a rss feed to the google spider, and the real page to my visitors. why i would do this? because its just a simple one-page with some adsense for a idle domain-name. is it blackhat?
Blackhat - No. Dumb - Yes RSS is great for altering the text content on a page. But let's say Google also uses the "last modified date" of the file in it's index decision to determine if the page needs to be re-indexed. RSS does not change the "last modified date".
Google can not read the last modified date from your pages. And it doesnt make sense. most of the pages online are dynamically generated with asp/php or the like. those files do not change, the content they output does.
I agree. But if you are not submitting your site with a "Google Sitemap", how does Google know when to come back and re-index? My use of RSS has not given me an advantage in any way. It's great to change content on the fly, but so is ASP/PHP. What you are trying to do is change the text on the page so Google will index it more often. This is what the Google Sitemap is used for. But if you show Google one page and the user another, that's clocking.
Definitely considered black hat if you are showing users something other than what you serve the spider. Catanich meant to write "this is cloaking"
Yeah, it's generally 'bad form' to show spiders one thing & human visitors another. This is one trick that might actually bring you some bad karma.
of course , it will consider as black hat. google is visiting your site with a known user agent and googlebot is also visiting your site as normal user (without a user agent)