How often to adswap??

The problem with ad swapping is that 99% of the swap swipes are scammy fulff that your list will see right through.

But, if you don't care about them because they are just "freebie seekers", then I guess it doesn't matter.

But I have to wonder why you think someone would want a list of "freebie seekers" that you don't care about?

If you're follow up sequence is great you can always convert those
'FREEBIE' seekers into hot paying customers.

You could:

Send an awesome free gift as promised in the 1st email you send.
(with a nice message that tells them they can contact you with any questions or concerns)

Next message can be asking them whether they got their FREE gift ok and remind them
of how they can contact you again.

Third message can be thanking them for joining your email list and to look out for the
next message that is the next day because this next FREE gift can really help them
take things to the next level etc etc.

Fourth message is a link the FREE gift YOU promised them that has the price on it
as it is a sales page but you are giving it to them for FREE!

This then links to a resource page that has all of your other "PAID" products listed
and you are letting them browse through your shop window.

Next message is a reminder of the FREE product and again you are directing them
to your paid products without giving them the hard sell approach.

Hope this helps you out in some way my friend!

Regards
Gavin