Ranking for "synonym" terms on separate pages?

[bizzer]

(My title says "synonym" but it's not exactly the most accurate word, but works best for the title_)

I have a site that ranks #1 for a term, and let’s pretend it’s “cheap phone”.  It’s also ranks #1 for “cheap phone service” and #3 for “cheap phone plans”.  These are all the home page with those rankings

I have a sub page whose natural title would be “Cheap Phone Plans” or “Cheap Phone Service”. I have it named something these and it is not optimized for either of these terms because I think it would be best to not mess with the good rankings I have already for those two terms

So here’s my question:  what would likely be the outcome if I optimized that subpage for “Cheap Phone Plans” or “Cheap Phone Service”? If Google began to direct searchers of this term to my subpage rather than my home page, would my home page lose some of it’s ranking with it’s main and most popular keyword, “cheap phone?

Thanks!

[Andy.Drinkwater]

What you want to be careful of it falling into the trap of keyword duplication / keyword cannibalisation. This is why it's important to ensure every page is well focussed.

To answer your question, Google only really wants to deliver one of your pages for a desired term, so it is very likely that the homepage would drop if you were to optimise the internal pages. That said, it's not always a bad thing, because someone searches for "Cheap Phone Plans" and are taken to a page just about that, can help convert more readily - as long as you do the work to the page, of course.

-Andy