I've been running my website www.backcountrysecrets.com for about 2 years now. I had my traffic up to about 100 uniques a day, but it all of a sudden dropped in half. The only things I have changed are I am now doing URL rewriting whereas before I was passing a querystring for the point details, and I have AJAX enabled parts of the site that weren't really getting traffic anyway. I thought URL rewriting was supposed to help with search engines, not hurt. Any suggestions?
I have to ask did you 301 the old URL to the new ones? if not Google may see them as 404s. If this is the case then your site is for the most part starting over as your new URL's have to get indexed and placed in the SERPs. What does Google Webmaster Tools show?
you can compare how many pages are indexed from your site site:yoursite.com if google sees 401 pages are removed from index
Many sites have been losing traffic it's difficult to say what caused it, google may have de-indexed some of your pages, you should continue to build backlinks.
Not sure how to 301 old URL's, but if you try to visit one of the old URL's it will redirect to the new URL on the Server Side. Out of over 2000 pages, Webmaster Tools shows 3 unreachable URL's, 11 HTTP errors, and 1 Error in my sitemap. I have fixed these problems and am just waiting for another crawl to take place.
1. As i know Ajax is the one that against SEO page. Not really like flash, but pure html would be great 2. and yes you decided to waiting for a crawl right ? i sugest you to submit sitemap once again cheers.