I have a site which one day will rank around 50 - 60 in google for a particular search term then the next day at 500 - 600. A few days later back at 50-60 then again down to 500 - 600. Any explanation for such behaviour?
It's googl dance! It is normal especially for new optimized sites, sooner or later your site will be place on its right search engine position. Just continue building using your keywords as your anchor text. Hope that helps!
it happen to my site also it was 5th on its keyword and now it happened to be on 16 or 17 dont know what goog is upto.
Few years old, ranks well for other search terms but only recently I started targeting a particular search term by building links with that particular keyword.
Perhaps, some of your competitors are doing well in their link building...Try to keep on getting relevant backlinks and be sure to target your keywords properly.