E-mail is best for me for initial contact. When I'm researching ladies to see, I will contact maybe half a dozen providers with e-mail. I do this for several reasons. First I like contacting multiple gals in order to come up with a Plan B list. Second, it allows me to clarify anything that might be vague on their website/ad. Third, it allows me to also find out which ladies are actually responsive to inquiries. Fourth, it allows me to find out who is actually available when I'm free. Finally, it also allows me to get a "feel" for the provider. How does she reply? Is she matter of fact or enthusiastic. It sets the stage for a conversation and really helps me determine which provider I actually want to see. You can't do this with a phone call. With a pre-paid hobby phone, I can't be making initial contact with 5-10 providers I might be interested in. I reserve making phone calls for the 1 or 2 girls who make my "final" cuts. BTW, I despise the practice of not having some sort of phone conversation before a date. I don't mind texting. It has a purpose, but talking with the provider is VERY important. It helps build a bond.
To me this is kind of a grey area, emails and texts leave a paper trail once its written and sent its there. From a legal point if a person is being monitored by law enforcement or another agency all they need is a warrant and can gain access into your phone and email via service provider and collect evidence and use that against both parties once its written and sent its there something to think about! Now whats the probabilty of this happening to you is any ones guess but it can happen.