New domains vs old domains

Hello,

I have 2 new domains (2 years old) and old ones about 5 years old. When I submit new sites to search engines and social bookmarking sites every two days, my new sites don’t show up on Google anymore.

Old sites are ok. In other words, it does not matter how often I submit new content or pages o search engines or social bookmarking sites, they are still indexed good.

So, I don’t think it is a good idea to keep submitting and/or updating for new sites.

Any advice is appreciated.

Thanks.

new become old over time. IMO keep up the marketing for new ones.