in my point of view, it provides appealing look to your urls increasing the click thru rate. viewers tend not to click on long links specially with those $, %, or number character with it. Also there are some site that limits the amount of character you can input, this helps you post your long links in it.
Tiny URL has no extra purpose than to cloak the actual affiliate URL. This is done sometimes to accommodate the URL in a box meant for it in case the URL is too long.
Tinny Url has no SEO Value but it's Good for where is characters limited like on Twitter you have only 150 characters allowed to write that case it will make your original url short
In short: 1) To hide ugly affiliate links 2) To use where your characters are limited (like Twitter) 3) If you're spamming, your real link may be blacklisted. 4) It is easy for someone to figure out your promotion methods by looking up your link on google.
I advise against URL shorteners, unless they are provided by the service (meaning the service that the link is on shortening the URL). Why? It looks more reliable and trustworthy. If it is shortened by Youtube, I know it's somewhat safe (because Youtube is a reliable source), whereas something else like tiny url could be taking me ANYWHERE, appropriate or not. They are, however, still good for some occasions.
For it to fit for the micro blogging purposes it is just about making your URL shot, usually the URL's does not make any sense?
In many microblogging site long url is not accepted so for submitting or posting link that long one is converted into tiny url and then link is submitted.
tinyurl is not useful for SEO purpose because this link not create back-link for your site but it is good for posting on twitter, facebook and get you heavy traffic to your site though it.
url shorteners are a joke if you ask me. The only thing they are good for is text messages and twitter limited types of sites. If you feel the need to hide or cloak your link by using a shortener to hide it then most likely you are likely up to no good. Otherwise if you are not limited 140 character site why are you worried about hiding your link.
i agree..there is no use tiny url for SEO, it's just play ther rule of posting lionk on social network.