By Duncan Bartlett
BBC News, Delhi
Florists are expecting to do record business.
Valentine's Day is now firmly established as a special date in India despite complaints from some radical religious groups that it is an affront to its tradition and culture.
Couples who are planning to go on Valentine's Day dates in some parts of India risk having their romance disrupted by religious radicals who are trying to prevent men and women meeting each other in public.
The right-wing Hindu organisation Bajrang Dal has said it will oppose Valentine's Day celebrations in Madhya Pradesh "tooth and nail", claiming the day reflects a Western phenomenon which is destroying Indian culture.
The group also encourages its members to burn Valentine's cards and members have put up billboard advertisements asking young lovers not to hold hands.
Traditional Indian society does not approve of public displays of affection between the sexes, including hand-holding and kissing.
Another Hindu hard-line organization, the Shiv Sena, has said it will photograph couples caught expressing their love in cinemas, cafes and shopping malls and hand the pictures to their parents.
More than £140m will be spent on Valentine's gifts this year
However, the message of this small number of protestors is ignored by the majority of people, especially the young. In Delhi, smart restaurants are fully booked for February 14th and card shops and florists are expecting to do record business.
The Indian Post Office is also cashing in.
It has launched a set of floral-scented stamps for Valentine's Day and hopes this will encourage people to send letters and cards to each other, rather than relying on emails and text messages to express their love.
Valentine's Day is a relatively new concept in India but it has grown in significance in the past five years.
As India's economy booms, many young women have found that financial independence brings with it freedom of choice when it comes to relationships.
In the past, the key decision on who a woman would marry was usually made by her parents.
Now though, many professional and educated women follow their own hearts when it comes to romance and young men have discovered that Valentine's Day offers a useful opportunity to lure the girls their way.
Businesses are happy to cash in.
The Indian Post Office is hoping to cash in with a new set of cards
The Retailers' Association of India estimates that the total spent on Valentine's Day gifts this year will be more than 12 billion rupees ($270 million, £140 million).
India's largest chain of card shops, Archie's, is producing more than 300 different types of Valentine's Day cards this year.
Some of them come with detachable love hearts which can then be used as mobile telephone accessories.
There is also money to be made from people who do not have a sweetheart but want one. Internet dating sites have grown in popularity in India.
One of the most successful, Fropper.com has two million members and says February is the most popular month in which to join.