What are the best strategies anyone is effectively usining in regards to social and bookmarking sites?
The main strategy when using social and bookmarking sites is to retain the visitors so they come back again. They way you do this is by page optimization in displaying messages that they should subscribe to your feed or by an email subscription system
but to be honest, with my experimentation with it, the results don't justify the hours of manual work that it takes to bookmark your sites. So, as a result of all that, i've gone to an automated submission process. If you want more details on what i do, pm me and i'll give you more details (and if you like it, you can give me some rep!! )
for social sites you need to offer the people on your friends list something they want to look at and will be interested in and get them onto your page. make your social profile like a person and not a company imo. and also remember that social networking sites have no follow on links so only reason would be to gain direct traffic from your profile, and even this can be seen as bad if a certain % of traffic comes from these sites.