Well there is no such tool which can be helpful for you to increase followers of your own niche for either of these sites. However you have to do smart viral marketing techniques to implement them on these sites to increase your followers or friends. Infact there are sites like twiends.com who can get you good amount of followers, but they will be random people who might not be in your specified niche.
there is a tool in twitter to increase followers but its not free one of the best twitter marketing tools are tweet attacks tweet adder atomic tweet tweet tank
It depends on your intent for such a tool, if to generate sales immediately; then do it the old fashion way - you need to do it the personally as you need to be fully engaged with your followers. I have been using tweetaddersoft for some time now, great tools to get followers in twitter. I have about 500 pre-scripted tweets, and post two or three a day. I am using it to generate traffic to my sites and when the visitor opt in for my freebies, my sales process will begin. http://www.tweetaddersoft.com
Such tools used to exist but it should be useless to search them after the fact that twitter has handled spam quiet nicely.
according to me twitter is not best for increase traffic ... but facebook is very nice.. i have used both ..but i get nice traffic from facebook ..
There is no tool i ever heard which can build friends it only can be done personally. for this, you just need to engage your visitors by providing updates world wide and having fun.
Check out the Twellow Directory, which makes it easier to find other user accounts based on keywords (in your niche).
What does not make sense? If I may help. I use http://www.tweetaddersoft.com to automatically follow and unfollow in twitter, within the software I have about 500 unique tweet which the software automatically send out tweet at 8 to 10 hours interval (2 or 3 tweets a day). When I have something to announce I will send out tweet manually and direct visitors to my announcement site, without fail each time, I will get a surge in traffic immediately after the tweet; ~ 1% of my twitter followers. Hope it helps.
I beg to differ. Check this out http://en.wikipedia.org/wiki/Spam_(electronic) the keyword here is "unsolicited". When we used autoresponder to broadcast same messages to our lists, do you also consider it a spam? I keep in contact with my list once a week to forthnightly, similarly 1 to 3% will respond each time. 2 or 3 posts a day in twitter is not excessive, especially when the daily posts are unique for that day and it is sharing my thought and opinions. I will consider spam as frequent multiple posts (say 5 or more) within a minute. When I receive such, I have the option to unfollow manually.