I’ve been manufacturing a nutritional product for about a year now. We started out giving out samples to like-minded communities and then moved into a few small nutrition stores.
The reception to our product has been good but we have a fairly small footprint as of now. Ideally I’d like to do some online targeting and find like-minded communities there, as well.
What are the best customer acquisition channels for my product? I realize there are a lot, and many will be a waste of money and time for me, so I am hoping to find a few acquisition channels that will have the greatest effect for my startup.
You need to be on Amazon, perhaps create a free affiliate program after yiuyou set up. Make SURE ALL your Social Media is current, and comment in like mind communities ,the more the better... RollUp your sleeves and go to work. Being an Entrepreneur isn't easy.
Congratulations on your initial success in the marketplace! By starting small and learning how to service your accounts you can apply those lessons and begin to scale. That said, you must determine whether you want to sell to resellers via the "channel" or go direct to consumers (AKA Amazon or your own web store). Based on your question it sounds like you want to expand through a B2B channel sales strategy.
I am not a big fan of Google Ad words or other such general services. There are interesting solutions which provide retargeted marketing for specific consumer groups as well as other providers that employ other e-marketing science.
That said, working "old school" should be your focus. I did one internet search with the term "list of independent nutritional stores" and came up with many site links including http://www.naturalfoodretailers.net/member-directory which claims "over 225 Independent Retailers with over 350 store locations." If you want bigger stores, Huffington Post even did an article on what they think are the top 11 stores (http://www.huffingtonpost.com/the-daily-meal/the-top-11-health-food-st_b_10483960.html).
Depending on your ability to service such locations (how much inventory can you supply) you should be able to start to scale sales using these local retailers who have local customers. Again, I presume from your question you want to go B2B not B2C.
I also note several associations that you may qualify for membership in. Properly used (ie active networking and participation), association can be very valuable investment for your organization.
There is no silver bullet to acquiring customers, but focus, hard work and learning from past successes & failures will pay dividends in future success. Quality lead generation is not easy nor is closing B2B sales/partnerships. If it was, everyone would do it.