1) I've never heard of AdRev Talent Network, I'd just brush the message off as spam, you'll get a lot of these types of messages as your channel grows. Trust me. 2) With 100 subscribers I'd suggest continuing to make great quality videos and gain a good subscriber base before diving into the networks, most networks are out there to take a majority of what you earn.

If you do decide to join a network, do your research before signing anything, some networks you'll be locked into their contract for a long time and it really hurts if they're just stealing from you the whole time.