Overall, I think that relatively few of the links list owners are willing to take the time to do whois investigations to see what domains belong to what submitters. Those who do will have rules that say that a webmaster can only submit one site/day. You may want to tell your girlfriend that she cannot submit to those lists, or you'll end up being blacklisted.
The rest of the links lists will have a rule that says something like you can only submit one or two sites PER DOMAIN per day. Those would be safe for both of you to be submitting to. Just look at the rules and see which ones are safe for both of you, and which ones aren't.
|