said 1 year, 4 months ago:
TweetReach is only going to tell you the number of impressions a tweet gets. That’s equal to the number of followers your followers have. Only really has value of your tweet if retweeted. There is no time investment, its a quick report online.
Twitalyzer give you more information, including some demographics. Again a free report online.#KnowYour Followers is not free and if it ain’t free… From the outside it looks like there is some good information, but I really don’t care for the pricing.