Do not use pop ads or anything annoying if you already run a paid site.
Just use some links to cams & dating like what I have done with voyeurboss & bbcboss
They are not invasive and if someone really wants cams or dating they will see and click on that link. Don't force people to see things especially if they have already paid.
If you force them your subs will start to drop.
Don't be greedy with porn sites and money.
Make a good site and they money will cum
see what i did there? hehe