Because, it's inbred through genetics to focus on movement for primal reasons. Today's humans are very much like our ancestors. We utilize our inherent tendencies when moving through a forest of ads. Action words command our attention. Notice that one ad contains verbs and the other doesn't.
Verbs show action.
Spend a goodly portion of your time, as I have here, on your ad title or the reading process may end rather than start here. To generate attention, consider the flash value of the words in your ad's title. An awesome ad must cause the reader to stop and to investigate your product. The body of your ad must have cognitive appeal. It must make enough good sense, to be worthy of a visit to your site, an email info request, or just to continue reading the ad.