If you are accepted into a startup accelerator program and you give them equity in your startup, you can be certain they will try damn hard to make that equity worth more to you, and by extension, to them.
But an accelerator doesn’t have a magic secret ingredient; they can’t turn bad startup ideas into awesome startups. At best they can help you experiment, learn and develop products faster. Their network of other founders, advisors and investors can help you make connections too.
Maybe that’s all your startup needs to succeed; maybe it’s something you would have developed yourselves anyway; or maybe even that isn’t enough to succeed with the ideas you have, or the problem you’re trying to solve, or the customer you want to solve it for.
So the most an accelerator program can offer you with total certainty is the opportunity to achieve the outcome your business was going to achieve anyway, only faster.
If it was always going to succeed, it could succeed bigger by going through an accelerator. But if it was going to fail, an accelerator should accelerate that failure. Which sounds like a bad thing — until you realise that failing fast means failure costs you and your shareholders less, since the majority of costs of a startup aren’t in capital equipment or infrastructure; they’re in salaries, service fees, marketing and cost of sales.