A transparent referral link is quite OK. I think.
But to be more precise, with TVE you usually earn viral points, which you can exchange for BTC, NXT or, better, for BLITZ (with 5% bonus), but only after you collect 130 viral points. Referral gives you 20 viral points.
You can also use TVE to promote your site/blog etc
My affiliate URL is https://theviralexchange.com/?ref=311 :-)