BTCJam has too many defaulters, hence the sharply reduced volume on the site.

Would recommend other avenues to invest and grow your btc.

Invest globally with bitcoin. Wealthfront for bitcoin.
http://themerkle.com/bitcoin-investment-startup-keza-unveils-ios-beta-app/
https://www.producthunt.com/tech/keza
http://getkeza.com/ (It's free to apply for a Keza account)