cnvi - 5:51 pm on Jul 8, 2011 (gmt 0)
Absolutely. The search engines arent going to ding you for this. What they are looking for is HIGH volume LOW quality. As long as your volume (acquisition rate) remains natural its ok to get the relevant link from the general directory.
Obviously if the entire domain directory is relevant, get the link even if they ask for a link back. Always get the relevant link even if you reciprocate.