Very simple suggestion to raise the character limit in Sales Chat only to 200 instead of 150. Due to requiring links, it can eat up easily 1/3 of your available character limit and make avertising especially difficult.

I am not accepting "Just use tinyurl" as a counter-argument against this for one very major reason.

You cannot guarantee where tinyurl links go prior to clicking.
Tinyurl links can easily be used to mask malicious urls, such as phishing and spyware sites.

Alternatively, consider URLs not counting toward chat character limit at all, if possible, with a limit on number of links (perhaps 3).