I was attracted to 5 Tacos reviews with this service. It is a good alternative but needs a lot of improvement. It has an inbuilt wordpress plugin but Integration is not solid. Limited options. Here are few points I noted.

1) You can't auto generate reward coupons directly from the wordpress when someone qualifies for a discount.
2) Sometime it doesn't pop up on website. I tried multiple times on many different interfaces. (Mobile, Laptop, Ipad etc.)
3) Embedded option is not working 100%.
4) There is no just widget option.
5) You can not generate multiple referral programs of different type on one website.
6) You can not monitor stats directly from Wordpress interface, you have to go to girafi website to track the stats.
7) You can't add tems and condition options within the pop up.
8) you don't have a full control to design the Pop ups. (eg. Background colour, Shape, emojies, font styles etc.)

There might be a few more to include. But I found I was looking these main features which I didn't find or may be hiding from my eye even after I tested too many times.

Hopefully I would find what I am looking for on Appsumo in nearest future. Or hopefully, Girafi will be become solid and feature rich so I can't resist myself from keeping it. Fingers Cross!