Get Many Backlinks for Posts
Yeah, Its a fact that Google will quickly come to know about your old posts, if they get enough high PR backlinks. So try to get as many as possible by informing your post while commenting on blogs, forums, etc.
Second Method: Use Your Feed Smartly
As I mention, for Blogger, the only way to submit sitemap is Blog-Feed. So you can use your feed to get attention of Google towards your Old Posts. Just add your favorite posts links in Feed Post Footer and get them indexed by Google. If you don’t know how to add link at Feed-Post-Footer, then my quick guide can help you to do so in just 2 minutes.
- Sign up with Blogger. Then navigate to your Blog settings
- basic HTML, so you can use text to show your favorite Posts links.
- When next time Google will crawl your website, it will automatically come to know about those Posts.
And second advantage is that your new feed readers will also come to know about those posts.
Update: I just noticed that this service won’t be activated, if you choose to show only short feeds. But I recommend you to go for Full Feed. It will help you to get more Feed readers and in turn with Feed Advertising you can earn a lot.