Charla and Brad Muller of North Carolina did just that and say it helped their marriage grow stronger.

Amazon.com

They had a solid marriage and two wonderful children, but over the years sex was not as much a priority. Charla wanted to give her hubby something special for his 40th birthday, so she decided to give him the gift of sex. She pledged to have sex with him every day for a year.  "When I offered my husband sex every day for a year to celebrate his 40th birthday he literally fell over. After hearing the words, Brad slipped on a toy on the floor and landed with a thud. As I had spent so long thinking about an exciting present that I thought he would love, I was confident he would say yes. But to my astonishment, Brad refused my offer. He said: “It’s a great idea, I just don’t think you really mean it.” She meant it and they did it. Their marriage is now stronger than ever and she recommends it for anyone who has grown out of touch with their spouse.  She's written the book "365 Nights, a Memoir of Intimacy" describing the journey.