E-fairness legislation (ie, taxes on internet purchases).

I am completely opposed to every form of "e-fairness" legislation, as you call it, that I have ever seen.

I oppose it for both philosophical and practical reasons. I'll gloss over the philosophical reasons and just say that the act of determining what is "fair" is a moral/philosophical act, not one of objective calculation. (I could go on for 14 more pages, without plagiarizing anyone else's work, I might add.... But I need to go to work today too.) As a simple matter, is it "fair" to charge an resident of a state without a sales tax a sales tax that will benefit people in a state they never set foot in?

If I didn't object on philosophical grounds, I would object on purely practical ones, and they would be sufficient. As background, I have worked at the intersection of IT and Government for the last 15+ years. All one has to do is START a high-level analysis of the task and compare it to "simple" ones (like making the ACA work, The VA see patients in a timely manner, Processing OERs, etc).

As a start, realize that the sales tax you pay at the local grocery store has multiple components. First there is a locality (city/villiage/whatever) tax, then there is a county tax, then there is a state tax. Unless any of those are missing. Oh, and there MAY be other taxing authorities adding addition taxes (not at the grocery store, probably) - Think transit and tourism charges added in certain high-density areas. All that is complicated enough - and granted, there are THOUSANDS and THOUSANDS (I'll come back to that) of individual systems that calculate those numbers -- with greater or lesser accuracy.

NOW, you have to calculate the "fair" sales tax. Again, this is primarily a philosophical question, but from a practical view, some of the factors are - taxes at purchases destination, taxes at vendor headquarters, taxes at warehouse location, taxes in locations transited (unless it's "fair" to make use of roads without paying...), taxes at location of ultimate use (unless it's "fair" to purchase something as a gift, knowing you are going to send it to someone in a higher tax area.). I'm leaving a lot of other factors out of the "fairness" calculation, but you get the point.

NOW, you need to take the gestalt of ALL of these individual systems. And yes, there are thousands - they have to be at the lowest applicable level in order to calculate accurately. Oh, and they all use different technologies and have different standards. And they all update on different schedules. And have as many exemptions and special situations as the military pay system. Need to pay tax on a X, unless it is to be used in a business that does Y. Unless you have a sales tax exemption form (which Oregon residents often do when the shop in Washington), etc.

NOW you need to audit the holy F out of it, because no locality wants to give up a dime of their money. In addition to the auditing, you now need a federal agency of sales tax equalization & distribution. Which is either funded out of the federal budget, or a surcharge on taxes.

This is hard enough (and error prone enough - though you usually don't hear about it) at the state level. It isn't just 50 times more complex to integrate. Consider multi-state compacts, bi-lateral tax agreements, and the fact that EVERY jurisdiction can change their tax system however they see fit, whenever they see fit.

This system would make the federal income tax code look simple by comparison.

I would sooner support a VAT (meh).

Penultimately, just as you CAN donate to the federal government, if you feel so inclined, you can do so at the state level.

Finally, if it helps, you could just obey the law. Search your state's name and the term "Use Tax." You will quickly discover (I can't speak for EVERY state, but I think all....) that you are legally required to pay a "Use tax" on anything you purchased in a lower tax locale that you are going to use in the state in question. ;-)

Fairness is a self-relative word in this instance. Convenience is a factor. Shipping and time is a factor. Returns is a factor. In some cases it comes down to who is the beneficiary of the tax, and who ends up with the money? Does the state where the purchaser resides end up with the tax? Does the state where the seller does business end up with the tax? Do both states end up with some of it?
The brick-and-mortar stores have immediate sales ... you walk in, find an item, pay, and walk out within a short time period. Say I'm doing a garage project and I find I need some hardware to complete the task. I run down to Lowes, Home Depot, or Ace Hardware and obtain what I need, return home and finish my project. I pay a tax on my purchase but wrap up my project on my time. If I go on-line to obtain my hardware, maybe I find it cheaper and without tax, but I accept that I wait & sometimes pay for shipping and do my project another day.
Most people today are all about convenience. I realize this will not be the same idea - but in my business, I receive several calls a week asking me what I would recommend for someone to purchase to get rid of their bug or pest issue ... the D-I-Y approach rather than have me come out and fix it. The 'easy' factor is not always the best way to solve something, but most often the approach people take. I see it as short sighted. I cannot compete with the price of a can of Raid to solve an ant problem, but some people expect my price to be close to the cost of that can.
Now you look at the sales tax issue - when I perform a service or sell a product, I must collect sales tax. I don't get to keep that money, I have to send it in to the state every quarter when I file my sales reports. Does that raise my prices to clients, of course ... but clients see a higher price and most often do not realize I can't keep the money. If the "on-line" store avoids having to deal with the sales tax pass through, are they at an advantage ... maybe. I can be there today to fix your problem, you purchase on-line and you wait to fix your own problem. I've learned in business that while 'cost' or 'price' is a factor - help the customer see that SERVICE makes all the difference and is well worth that extra.
I am a big advocate of buying local and supporting the 'mon & pop' shops whenever I can, unfortunately most of society does not see things the same way. In the end, my opinion for or against the tax break has no bearing because what matters is what the consumer considers 'convenience'. I apologize for the long winded comment, but the question is more complicated than a simple answer.

Excellent point MAJ Dews. I would have to say that I feel the same way. Convenience is everything today. The more that technology enables us, the faster we are expected to go and more work are we expected to get done. Yet we still only have 24 hours in a day to do it. being able to shop and have it shipped to your door w/o sales tax puts a lot of time back in your week and keeps the money in your wallet. How do you argue with that? The decline of retail stores has been clearly in site for sometime. A few years ago just the sheer volume of stores competing with one another was ridiculous. Lowes & Home Depot within 1/2 mile of each other, 3 furniture stores on the same road, 5 major pharmacies within a 2 mile radius. Now that the fittest have survived, they have to compete with ecommerce, which as you point out, they are at an immediate disadvantage for.