I'd like to switch from a navigation bar (page 1, 2, ...) to a "show more" button. So basically the user will see only one page with a few comments and when hitting "show more" will have the next comments shown through some ajax calls.
But of course, if a bot looks at the page, I'd like the bot to see all the comments.
I'm wondering if this approach is risky in terms of SEO ? If not, what would be your recommended test to see if it's a bot or not ?
Another question is, if I get let's say 400 comments on a topic, how do you think a very long page compares to split pages using a navigation bar in terms of SEO ?
All the divs are served at one time (with gzipped text, that's not a speed issue) so the bots reads ALL the content every time but the users get to pick and choose what's visible to them.
A finer point can be a script thjat captures referrer search terms from any SE traffic and then ensures that those divs load originally as visible, with each occurrence of the search terms highlighted in some color that works with the page's look and feel.
Far from being an SEO risk for this particular site, it has become their bread-and-butter. It's been in place since 2003 and always been an asset. It really helps the end user!