So a question comes in from the P80 customer base, "my boss says that if we compress our content the search engines will drop us." If only we lived in a world were conclusions weren't jumped to based upon hearsay! But, alas, we at Port80 inhabit the same world as you do. So we will roll up our sleeves and try to help put to rest these unreasoning fears about how making your site faster might screw up your search engine ranking.
First off the compression and SEO fear.
Gzip compression on HTML, CSS, and JS such as performed with httpZip and ZipEnable (or mod_gzip for any Apache readers out there) is a transparent solution. When a browser (or bot) that supports compression hits a site it sends an Accept-Encoding header indicating it can handle gzipped content. If a compression filter sees this header it will compress the response content and the client should decompress it before doing whatever it needs to do -- including indexing, in the case of a search-engine bot.
Now if the incoming request is lying -- saying it can handle compression when it really can't -- then we might have a problem. In the few cases that is an issue, Port80 compression products of course have an exclusion list that can be set to say something like “if you see this User-Agent then don't compress, even if it asks for compressed content.” So, Boss, worry not -- compression will not hurt your search engine ranking. We should know -- we have some satisfyingly high rankings for certain keywords and we certainly use the stuff ourselves!
Second, the HTML source optimization and SEO fear.
In the case of white space removal and other size reduction methods for HTML, CSS, and JavaScript performed with a tool like w3compiler, again there is no effect on search engines. In fact, given that pages may not be fully indexed due to excessive size, removing clutter may get more content indexed. Search engines do not reward you for whitespace in your HTML source (nor do your customers), so dump it and stop worrying about your ranking.
Finally, the encryption/obfuscation and SEO fear
Port80 believes that client-side JavaScript should be optimized for speed and obfuscated for protection -- or maybe even encrypted. Unless the search engine is indexing your JavaScript this is no concern for ranking. If you are depending on JavaScript to run in the first place to output some content then that is already being missed by the search bot regardless of any obfuscation or encryption in place, since search bots do not typically run JavaScript.
The only real concern here is encrypting HTML content using JavaScript. If you use a tool to encrypt HTML because you are worried about protecting it then indeed you may kill your search rankings. We find it amusing that some companies that sell such client tools actually don't use their own product on their site, presumably for fear of killing their listings!
Next time, witness a Port80 employee meltdown when one of us encounters Search Engine Experts in the SeaTac airport!