You said you don't have any data backing up your decision. None? No data whatsoever? Maybe there is some data if you go looking? If you literally have none, how can you possibly go ahead - unless it's really a case of do it in a day, throw it out there, and see what happens.
Joe Leech's decision diamond has 4 dimensions
- Qualitative User research - research insight, customer request, unmet user need, jobs users do
- Data - analytics, trends, a/b tests
- Business value - alignment with strategy, goal, metrics, vision
- Gut feel - feels right, SME opinion, emotion, stakeholder push. How many people's gut feel?
As Joe says
If the answer to all four dimensions is a yes, build that next. Does
it meet three of the four? Then build that right after. Two
dimensions, further down the priority order. Only one dimension is a
yes? Either park it or investigate further in one of the other
dimensions. Run some qual or quant research.
If there is only one dimension with a yes, don’t do it. Especially if
that dimension is gut feel.
Joe also some advice elsewhere about whether trying something out is a reversible thing or a one way door. If it's reversible - there's more inclination to just give something a go.
Go on 80%
Joe also says you don't have to be 100% confident to go ahead with something. If you're 70/80% confident then that's probably good enough. If you wait until you're 90% confident you're probably being too slow and losing your edge.
Also - don't rely on what people say :) If 6 participants say they'd use a feature, that doesn't mean any of them will, let alone the others!