Here is a freebie you won't have considered.

Neither Rocketmiles, PH or Kaligo can give clients VAT / sales tax receipts, at least in Europe. As the VAT / sales tax is reclaimable by the employers of business travellers, this puts you at a huge disadvantage.

No employer would let an employee book a £100 room via Rocketmiles because the £17 UK VAT cannot be reclaimed. Book that same room direct and you get a VAT invoice from the hotel so the net cost is only £83.

You don't therefore get the corporate market. The private individual market is heavily promotional driven and you need to offer huge mileage bribes on every booking to offset the loss of points and status benefits from booking direct. These clients also have little long term loyalty and will rebook with whoever has the best deal next time.

It is a trickier model than you think.

Ps. For info, I work closely with Kaligo on my UK site and sell very substantial volumes of rooms for them.