Forget whether or not to put your keyword in it, make it relevant to a searcher and write it for humans, not search engines. If you want to have this 20-word meta description which accurately describes the page you have optimised (for one or two keyword phrases) when people use Google to search, make sure the keyword is in there. There is more likelihood it will be used by Google as your snippet description in SERPs.
Don’t underestimate these less popular keywords. Long tail keywords with lower search volume often convert better, because searchers are more specific and intentional in their searches. For example, a person searching for "shoes" is probably just browsing. On the other hand, someone searching for "best price red womens size 7 running shoe" practically has their wallet out!
Goals and Objectives. Clearly define your objectives in advance so you can truly measure your ROI from any programs you implement. Start simple, but don’t skip this step. Example: You may decide to increase website traffic from a current baseline of 100 visitors a day to 200 visitors over the next 30 days. Or you may want to improve your current conversion rate of one percent to two in a specified period. You may begin with top-level, aggregate numbers, but you must drill down into specific pages that can improve products, services, and business sales.