On top of this your site needs to have solid content and resources as I feel low quality sites will eventually start being, those that are manually link building anyway. (searchbrat.com)
The more technologically savvy, yet still low quality sites, will go one step further and send new members fake messages. (beyondages.com)
They also upload your resume to many low quality sites which means you will be receiving a ton of spam emails. (zipjob.com)