Especially if you’re paying for it!
Your new provider might send you a high volume of traffic, but is it quality or even real traffic? That is, will it click-through to your desired targets (sponsors, your own tour, etc.)? Find out if it’s verified, or if you can get more qualified (ie. likely to click-through and convert) at a lower volume…
What are the protections used or at least the sources for the traffic they will expose your ads to? Obviously, someone who is planning on sending bot, skimmed or misdirected traffic won’t come out and admit it. Find out also if they have a trial package so you can assess the traffic behaviour and metrics for yourself.
Pricing and packages. Is it CPM (cost-per-thousand-impressions), CPC (cost-per-click) or another form of bidding platform? It can depend what your reasonns for getting traffic are; some sites want to place many static ads in order to increase their SE rankings, others don’t care for that and want only traffic that will provide a return on their expenses.
Account control: can you get a walk-through or demo of the user interface first? A control panel or dashboard’s ease-of-use or intuitivity can vary from depending on what you are seeking to achieve, as well as to what you’re used to or simply from whether the interface is overly-complex. Some companies provide you with an account manager expert who will do everything to ensure a traffic customer’s success, while other customers can be a little bit more control-freaks and require full access to tweak and review statistics for themselves.
Advertisements or “creatives”: what are the choices? Are they banner networks, text-ad placements, pop-unders, pop-overs, can you use your own, do they have a selection of (generic) proven ready-made material, or other new (or old) types of ads? Do they offer them all, or just some, and will they allow adjustments towards or away certain types in mid-campaign depending on ad productivity?
Cross-targeting: what is offered? Countries, billing types, time or day (or both) adjustment, age groups (based on ad placement) and niches are all considerations.
Cost overrun protection: how can you make sure your budget isn’t blown too soon(with CPC or CPM)? Can you cap the volume per-day? Target periods? Prevent auto-rebilling prior to analyzing your data?
Again, what answers satisfy you depends on your reasons for acquiring said traffic in the first place, as well as your trust in the vendor and your own need to control the processes involved before you can just let it go and move on to other facets of your business