The most prevalent reason may be to obtain the contact information for your clients so you can notify them of any deals or news about your company. This is the #1 reason, as this is how you can stay relevant with your customers and keep them coming to you. Along with that, by notifying them of any deals that you may have, you show them that you are trying to help, making them more likely to come to you.
I found ProxyCrawl’s Leads API by far the best and easiest way to new leads. The best part about it is it won’t repeat any leads that you have already done. This ensures that any email you get will be new and applicable for your use.
Tried & tested. Definitely recommend !!