Apollo, Leadmagic, and Lusha (though a bit expensive) are great. After procuring the numbers, you can check if you are getting phone numbers or switchboard numbers. Reults can vary dramatically, even with similar %lead enrichment numbers.
Adding layer of qualification for ICP-fit and chances of a win before phone number enrichment will help you in 2 ways. 1. Keeping the costs in check. 2. Using multiple sources to enricha and validate such higher quality contacts.
Once the numbers are procured and validated, another area which will improve meetings per enriched contact is a multi-channel strategy (whatsapp/call/SMS). Multi-channel strategy helps in covering diverse user behaviour and preferences. Let me know if you need any help.
