I really loved Segment when they launched and recommended them repeatedly to anyone who would listen. I can no longer recommend them because of price and instead suggest people hack something together themselves or use Google Tag Manager. It's just not worth getting your company locked in even if they might give you a startup rate right now.
It was also really frustrating to us doing work in the political and advocacy sector that the their EU GDPR Data Processing Agreement explicitly forbids using their product for any of the things our EU clients would need like measuring petition signatures or donations to causes -- since those might be information about "political opinions" which their terms prohibit. This particular GDPR interpretation is somewhat unusual, we've negotiated workable DPAs with almost everyone else we've wanted to do business with but Segment was unmovable.
It was also really frustrating to us doing work in the political and advocacy sector that the their EU GDPR Data Processing Agreement explicitly forbids using their product for any of the things our EU clients would need like measuring petition signatures or donations to causes -- since those might be information about "political opinions" which their terms prohibit. This particular GDPR interpretation is somewhat unusual, we've negotiated workable DPAs with almost everyone else we've wanted to do business with but Segment was unmovable.