For what it's worth, I use a ton of alt data vendors (paying over a 50k a year for the feeds), but I have declined to use even more. These are guys that come and claim to have actual predictive power based on X non-market data (text mining, cookies from sites etc). In terms of research, the threshold is even higher, so you have to distinguish yourself somehow.
Thank you - do you run a fund? Can you describe please how do these guys usualy approach you? do they set up face to face presentation? how did they eventually got to sell their feeds? or did they find you on soem conference?