Nope. I've yet to run into anyone actually interesting through posting an ad on a dating site.
Back in the day, before I realized the dating sites are funded partly through ads and partly through member payments, I put my AIM screenname in my eHarmony profile. Now, the site said such things are prohibited, and each newly-created or -updated profile would be reviewed over the next few days. *drumroll please* My profile was up for over a year before I got an email from the admin saying my account had been deleted for violating their rules.
I just had to chuckle. It took them a year? Maybe the admins there don't actually read the newly-created and -updated profiles.
In any case, I wouldn't put an alternate method of contact in a dating site profile now if the site prohibited it.