RE: Amazing website that invests your spare change into cryptos! + Giveaway!
While I do understand the concern over giving access to the bank account, it's not at all uncommon these days as there are numerous services out that utilize your login details for a variety of services. There is definitely a huge market for any service that makes handling money and investments easier.
A company out of Canada, UseMyBank, was actually one of the pioneers in this space, utilizing the same bank account login protocol for limited bank account access. I worked with them for more than a decade - and when we first started - everyone said that no one would ever log into their bank account and grant us access for ANY reason...guess what? They did, and spawned an entire industry in the payment processing world.
A couple of suggestions from an old broad that has been down this path before: focus more on the security aspect in your sales material. This is critical! Host the video on your website - not YouTube - and have a step by step graphical overview of the process as well.
This will help a great deal with conversions.
But I think with the right marketing, you really have a winner - this is the easy no brainer way for people to invest.
Kudos and good luck!