LeadFuze uses third party data partners and in-house crawling to aggregate, match and verify real-time company info, emails, mobile numbers, social profiles and more.
They have a cool feature called FuzeBot, which can be set on autopilot and drip new contacts into your CRM as it finds them.
TaskDrive supports sales and marketing teams by providing personalized lead research, data enrichment and account-based insights.
If you need a very high-touch list building service then this one's for you. You get assigned a researcher who allocates 40 hours/week just to you.