I've tried other lash serums that made my eyes sting (I wear contacts), caused pigmentation under my eyes, etc. While I saw some results from those, they were short-term because my user experience was otherwise so poor, and I never ended up re-purchasing.
I'm on my 3rd or 4th bottle of Extra Goodie, and I always have a back-up waiting. The applicator doesn't load on too much serum (it doesn't seep into my eyes, and I'm able to put it on even without a mirror), the serum dries quickly enough to use before mascara, and I feel good about using such a clean formula.
I probably get complimented on my eyelashes now at least once a week - even on Zoom. They are longer, thicker, darker, and more plentiful - which is saying something for a typical Asian lash. When I curl them, they just about hit my eyebrows, and my mascara goes on clump-free. I feel like a commercial.
Offer gift-wrapping for gift orders! EG makes a great gift because longer, healthier lashes (and brows) is something everyone wants, but no one would think to ask for.