what does the spammer gain by making injecting a script that is actually brings more traffic to my website??

Question

I had wordpress website to my client and it was hacked by scriot that actually brings more traffic to the website that my client never dreamed off.
basically, the hacking was by putting a script in the header that add thousands of <a> tags referring to other websites and there is also thousands referring to mine.
basically you can find my website by searching about a lot of random things but not its actual content

Answer 1

If they were able to change the script completely like that you will want to look at your code just in case that wasn't all they did. Also theres a chance the guy was just helping out because there are good people like that if you would believe.