Well, that was fast. No more than a day or two after Twitter switched over to bit.ly as its default link shortener (from TinyURL), bit.ly is now the most popular URL shortening service. According to statistics published by Tweetmeme, bit.ly now accounts for 46 percent of all the short URLs on Twitter over the past 24 hours, while TinyURL’s share is down to 43 percent. Just over a month ago, TinyURL had an overwhelming 75 percent share to bit.ly’s 13 percent share. According to Tweetmeme, bit.ly overtook TinyURL sometime last night.

URL shortening services have come into vogue along with the Twitter’s rise because of its 140-character limit. Bit.ly, TinyURL, and others condense the links with shorter ones that are Twitter-friendly and then redirect to the original pages. Standardizing on one URL shortening service that can provide Twitter with the underlying data about the pages being linked to could help Twitter with its plans to start indexing those links. It is all about search and mining the thought stream.

Bit.ly came out of Betaworks, which was also an investor in Summize—the startup Twitter bought when it realized it needed its own real-time search engine

I wonder how much bit.ly is worth now.

(Hat tip to Jenna Wortham).