I just had an idea that if I post a few url such as this then will it be spidered by google.This particular link is not linked from the home page.So will it still be spidered because it has a backlink from an external site?
Yes, of course it will. That's about 75% of what SEO is all about!-) However, it is very unlikely that somebody will try to find you using the keyword "this" as a search term. Thus, it is much better to take one of those keywords as an anchor text which people would most sensibly use to find things you want to offer. It's up to you to find that out...
but as suggested, a proper keyword has to be optimised, after all to get benifit out of it. indexing, no doubt will happen with one or two such links here and there.
Well, since the link points to two pages, I don't really know which page would get the PR/trust from this link in google.
I just want to make it clear here that the page I posted in link "here" is not linked anywhere from its homepage,but it is just a dynamic url which I have provided a backlink in this forum post.So will this be still counted as a back-link.