I am also a big fan of Contactually but Marelle said above, it is important NOT to spam people.
Once you're marketing via these emails, not simply keeping in touch, you should really be using an email marketing service where people can easily opt-out. People ignore CAN-SPAM laws all the time, but you shouldn't. Not here and ESPECIALLY if you are emailing people in Canada because their laws are more strict than ours.
I only send marketing emails to people who opt into my list, but I do manage contacts in my CRM. It makes my life a lot easier.
Maybe CRMs aren't huge with shop owners here, but I'm a consultant outside of Etsy and that's how I make my actual income. I help people find the right systems. I wrote a post on the essential ones I think everyone should have here:
http://alaiawilliams.com/5systems