Unsolicited: not requested, welcome or invited
When it says 'links to unsolicited or undesired sites' I honestly have no idea what that means.
This appears to be bit.ly asserting it's authority just because it can. Your website looks fine to me. It's safe and doesn't contain any questionable or dangerous content. I think it does come off as a little 'spammy' - but then again, almost every sales page does. I do not feel as though you should change anything. Just tell them to re-review your site because it's definitely legitimate.
In the mean time, use this URL shortener: