Looks like that they can't automatically analyze pdf files (that are the most common) correctly, so if they get hold of your resume somehow they will spam you with some noise based on what they can find in your resume. If you are a researcher they will spam you with all the stupid jobs that have word "research" in it even if it is telemarketing. Looks like they also don't understand the difference between Physicist and Physician, etc. They are absolutely useless, you can find all the jobs in Linkedin, Indeed and many other sites. I tried to unsubscribe their spam but they keep spamming me, so I blocked their email addresses.