If we add in the word 'all' it feels like we need a comma. If we do, why?<br/><br/>This is a friendly reminder for you to send through a photo of the store, a write-up and optionally your signature to go in the advertisement.<br/><br/>This is a friendly reminder for you to send through a photo of the store, a write-up and optionally your signature, all to go in the advertisement.<br/><br/>Thanks