Can dynamic pages rank in search without internal links?

[JS_Harris]

Example

A website has a page that is dynamically populated using data retrieved from an API call. The site has a standard design with index page, categories and some related links, nothing out of the ordinary.

The dynamic pages know what to retrieve and display based on a variable in the link that brings a visitor to that page (ie: $_REQUEST["widgets"]). The page isn't spam, it also ads very useful content such as reviews from other places on the site itself, the pages rank well in search.

HOWEVER, if someone was to change the variable in the url and then linked to the resulting page from another site would search index the page?

Basically can a page that has useful content rank based on the power of incoming links only if it's not linked to from the site itself?

[phranque]

if someone was to change the variable in the url and then linked to the resulting page from another site would search index the page?

changing a variable in the url makes it a different page (possibly with duplicate content) but the SE's will eventually index all the urls they discover.

Basically can a page that has useful content rank based on the power of incoming links only if it's not linked to from the site itself?

i would assume that one inbound link probably carries more weight that one internal link.

[BradleyT]

Basically can a page that has useful content rank based on the power of incoming links only if it's not linked to from the site itself?

Yes and it's a good reason why you need to do a good job sanitizing input. Just think if someone put some nasty wording in the querystring and then linked to it and got that page to rank. It could be political slander, competitive slander, etc...

[phranque]

if someone was to change the variable in the url and then linked to the resulting page from another site would search index the page?

what i forgot to mention in my previous reply is that you should only serve content for canonical urls and you should redirect (301) everything else to a canonical url or provide another appropriate HTTP response.
a requested url that generates a 301 or 404 response will not be indexed.