Send custom offer you mean? I think so; for me its too early to send a custom offer when you don’t even know what the buyer needs.
Yes, the short attention span excuse is good enough and if I don’t get feedback, I will let it go.
I have had an experience last year where a customer ordered a gig and never looked back until 4 weeks after delivery, he came and left me a negative review saying I didn’t do as he wanted.
Of course, my policy is to give my client unlimited review, including refund if it comes to that, and I contacted him about what he wanted me to do, off again for another 2 weeks, that was when he replied. I made the corrections and sent the work again, he didn’t show up until 4 days later and now told me he was sorry about the negative review and asked to he change it, unfortunately, he couldn’t.
So, when I have a customer that won’t respond, like the case under comment, I would rather such a customer go, than keeping me endlessly hoping he would show up one day.