They gave you their number out of a sense of obligation.
You may have been chatting with them for quite a while on online dating sites.
Those conversations have been good.
But, they haven’t necessarily been blown away by them.
However, they do like your personality to an extent and find you fun to talk to.
Hence, when they finally give you their number, they may do it because they feel like you have earned it.
They may not have necessarily been excited to give it to you. They may have felt that it was time to take communication between the both of you to the next level and beyond online dating sites.
It was just the appropriate time to do so.
They may even feel that this is something that you would be expecting by now.
These girls don’t believe that you would be willing to communicate with them forever on online dating sites.
Hence, they may have felt that it was the appropriate time to finally give you their number because you had been patient with them and you had earned it.
They may now be taking ages to reply when you finally have their number because the thrill of communicating with you may have died.
Now that you have their number, they may have reached their climax with you.
In other words, these girls may feel that you finally got the prize in getting their number from them and hence, there is no more real motivation to reply to your messages so promptly.
It is like they have reached the climax of a movie and now they are in the epilogue.
The show is about to end and they are already thinking about getting to their cars in the parking lot and driving to the next venue of action.
The next venue of action for these girls could be the other guys who are sending them messages on online dating sites.
Now that you have won the prize of getting their number, they may start focusing more of their attention on the other guys who may be trying to win the same prize from them.
Hence, you begin to take a backseat in their minds.
As a result, they take ages to reply to you even though you finally have their number.
Another reason why girls on online dating sites take ages to reply when you finally have their number may be because they may be worried that you will want to meet them in real life sooner than they feel comfortable doing so.
Indeed, they may not even want to meet you in real life as of now.
However, they know that by giving you their number, they have taken their interaction with you to the next level.
Hence, they are worried that if they were to promptly reply to your messages, it will not be long before you start asking them to meet up with you in real life on a date.
These girls that you met on online dating sites may not want to put themselves in this position.
Hence, they take ages to reply to you even when you finally have their number because they don’t want to encourage you into believing that you should ask them out in short order.
By taking ages to reply to you, these girls that you met on online dating sites feel that to some extent they can delay the possibility that you will ask them out.
They are not at a place mentally where they want to meet you on a date in real life.
By taking ages to reply to you, they are hoping that they discourage you from asking them out or at least, prolong that inevitability.