Depending on the market, a bank is going to look at a combination of low-cost customer acquisition (particularly in strategic growth segments), mass-market desposit mobilization, credit portfolio growth and fee-based income. The respective weight of these, in terms of relative importance, will depend on the bank and its strategic objectives. It will also vary based in whether you are talking to an acquiring or an issuing bank. The best way to approach a bank is therefore to identify which core business element your startup is best positioned to support, and which bank is likelier to find the value prop attractive. I would suggest talking to the head of retail banking, the head of credit business and the head of acquiring business.