How do you promote when you have 500 messages in blogs and using rss reader ?

Upload RSS to all availoable RSS Directories. I upload a single combined RSS channel of all my blogs, consisting of over 800 posts/day. There's some traffic from there, especially those who are ********. Use Zimbio, too. I get tons of traffic from it.

I recommend "rsspect" as a starting point, and there are hundreds of other RSS aggregators as well.

One funny thing is, if you add your master RSS feed to your Facebook account (in Profile, where you can add Flickr, Picasa, Digg, etc.), Facebook will cache and create automatically posts out of each of your posts, even images will get cached. All your 1000s of friends will be ultra-spammed on their newsfeeds until they block/leave you. Funny though, most won't and will visit your blog posts within Facebook. Make sure each of your posts is loaded with Related Posts plugin - related posts retain their URLs to your website even if the post and the images are cached. Facebook won't ever expose those posts to Google though, huge privacy blackhole, and don't expect backlinks from this, just natural traffic.

RSSpect is a joke, the only true powerhorse out there is Yahoo Pipes.
It's for the true hardcore RSS scrapers/rewriters, with some programming background.
But you can do wonders with it. I do. I do some impossible stuff with it.