Originally Posted by wige

A "heavy" page is not good for search engines because search engines generally only allot so much space in their indexes for web pages. Web pages larger than the search engine's index limit will only have up to that limit of their content indexed. The limits are believed to be 250k for Yahoo, 500k for Google and 1mb for MSN/Live. One place you can check for confirmation is: Search Engine Indexing Limits: Where Do the Bots Stop? [Search Marketing] which details a study to determine these exact limits. I have seen documentation in Google Webmaster Help confirming their limit is currently 500kb for all but high PR sites, which are alloted 1mb or more, but unfortunately I have not been able to locate that document lately.